diff --git a/Makefile b/Makefile
index 75f552d..1fa080a 100644
--- a/Makefile
+++ b/Makefile
@@ -22,7 +22,7 @@ endef
 export PRINT_HELP_PYSCRIPT
 
 BROWSER := python -c "$$BROWSER_PYSCRIPT"
-VERSION := 0.1
+VERSION := 0.1.0
 
 help:
 	@python -c "$$PRINT_HELP_PYSCRIPT" < $(MAKEFILE_LIST)
@@ -71,14 +71,29 @@ docs: ## generate Sphinx HTML documentation, including API docs
 servedocs: docs ## compile the docs watching for changes
 	watchmedo shell-command -p '*.rst' -c '$(MAKE) -C docs html' -R -D .
 
-release: dist ## package and upload a release
-	twine upload dist/*
+fix: bumpmicro dist
 
-dist: clean ## builds source and wheel package
+release: bumpminor dist
+
+majrelease: bumpmajor dist
+
+bumpmicro:
+	bumpversion micro
+
+bumpminor:
+	bumpversion minor
+
+bumpmajor:
+	bumpversion major
+
+dist: clean format
 	python setup.py sdist
 	python setup.py bdist_wheel
 	ls -l dist
 
+format:
+	black kofi/
+
 install: clean ## install the package to the active Python's site-packages
 	python setup.py install
 
diff --git a/Pipfile b/Pipfile
index 275df4a..63e91d3 100644
--- a/Pipfile
+++ b/Pipfile
@@ -14,9 +14,15 @@ python-docs-theme = "*"
 watchdog = "*"
 argh = "*"
 pygments-graphql-lexer = {git = "https://github.com/lablup/pygments-graphql-lexer.git"}
+bump2version = "*"
+black = ">=19"
 
 [packages]
 kofi = {editable = true,path = "."}
 
 [requires]
 python_version = "3.8"
+# vim : set syntax=toml
+
+[pipenv]
+allow_prereleases = true
diff --git a/Pipfile.lock b/Pipfile.lock
index 073f7eb..582c8a4 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "13b5a019475ee9076d6011c5af968f03c230983ab9cde48aa233907c3eecfc34"
+            "sha256": "0648f88c35ffd8553adcd3ffed49722a983ab458a57ef3d0f4e3375c9fb2f256"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -62,10 +62,10 @@
         },
         "click": {
             "hashes": [
-                "sha256:2335065e6395b9e67ca716de5f7526736bfa6ceead690adf616d925bdc622b13",
-                "sha256:5b94b49521f6456670fdb30cd82a4eca9412788a93fa6dd6df72c94d5a8ff2d7"
+                "sha256:8a18b4ea89d8820c5d0c7da8a64b2c324b4dabb695804dbfea19b9be9d88c0cc",
+                "sha256:e345d143d80bf5ee7534056164e5e112ea5e22716bbb1ce727941f4c8b471b9a"
             ],
-            "version": "==7.0"
+            "version": "==7.1.1"
         },
         "graphql-core": {
             "hashes": [
@@ -76,9 +76,9 @@
         },
         "graphql-server-core": {
             "hashes": [
-                "sha256:04ee90da0322949f7b49ff6905688e3a21a9efbd5a7d7835997e431a0afdbd11"
+                "sha256:11fa8a434e1cd05d29709af29414b8b6f596925d26afe39eff33bd24a5f93605"
             ],
-            "version": "==1.2.0"
+            "version": "==2.0.0"
         },
         "idna": {
             "hashes": [
@@ -148,19 +148,19 @@
         },
         "pyyaml": {
             "hashes": [
-                "sha256:059b2ee3194d718896c0ad077dd8c043e5e909d9180f387ce42012662a4946d6",
-                "sha256:1cf708e2ac57f3aabc87405f04b86354f66799c8e62c28c5fc5f88b5521b2dbf",
-                "sha256:24521fa2890642614558b492b473bee0ac1f8057a7263156b02e8b14c88ce6f5",
-                "sha256:4fee71aa5bc6ed9d5f116327c04273e25ae31a3020386916905767ec4fc5317e",
-                "sha256:70024e02197337533eef7b85b068212420f950319cc8c580261963aefc75f811",
-                "sha256:74782fbd4d4f87ff04159e986886931456a1894c61229be9eaf4de6f6e44b99e",
-                "sha256:940532b111b1952befd7db542c370887a8611660d2b9becff75d39355303d82d",
-                "sha256:cb1f2f5e426dc9f07a7681419fe39cee823bb74f723f36f70399123f439e9b20",
-                "sha256:dbbb2379c19ed6042e8f11f2a2c66d39cceb8aeace421bfc29d085d93eda3689",
-                "sha256:e3a057b7a64f1222b56e47bcff5e4b94c4f61faac04c7c4ecb1985e18caa3994",
-                "sha256:e9f45bd5b92c7974e59bcd2dcc8631a6b6cc380a904725fce7bc08872e691615"
+                "sha256:06a0d7ba600ce0b2d2fe2e78453a470b5a6e000a985dd4a4e54e436cc36b0e97",
+                "sha256:240097ff019d7c70a4922b6869d8a86407758333f02203e0fc6ff79c5dcede76",
+                "sha256:4f4b913ca1a7319b33cfb1369e91e50354d6f07a135f3b901aca02aa95940bd2",
+                "sha256:69f00dca373f240f842b2931fb2c7e14ddbacd1397d57157a9b005a6a9942648",
+                "sha256:73f099454b799e05e5ab51423c7bcf361c58d3206fa7b0d555426b1f4d9a3eaf",
+                "sha256:74809a57b329d6cc0fdccee6318f44b9b8649961fa73144a98735b0aaf029f1f",
+                "sha256:7739fc0fa8205b3ee8808aea45e968bc90082c10aef6ea95e855e10abf4a37b2",
+                "sha256:95f71d2af0ff4227885f7a6605c37fd53d3a106fcab511b8860ecca9fcf400ee",
+                "sha256:b8eac752c5e14d3eca0e6dd9199cd627518cb5ec06add0de9d32baeee6fe645d",
+                "sha256:cc8955cfbfc7a115fa81d85284ee61147059a753344bc51098f3ccd69b0d7e0c",
+                "sha256:d13155f591e6fcc1ec3b30685d50bf0711574e2c0dfffd7644babf8b5102ca1a"
             ],
-            "version": "==5.3"
+            "version": "==5.3.1"
         },
         "rx": {
             "hashes": [
@@ -231,6 +231,13 @@
             ],
             "version": "==0.7.12"
         },
+        "appdirs": {
+            "hashes": [
+                "sha256:9e5896d1372858f8dd3344faf4e5014d21849c756c8d5701f78f8a103b372d92",
+                "sha256:d8b24664561d0d34ddfaec54636d502d7cea6e29c3eaf68f3df6180863e2166e"
+            ],
+            "version": "==1.4.3"
+        },
         "argh": {
             "hashes": [
                 "sha256:a9b3aaa1904eeb78e32394cd46c6f37ac0fb4af6dc488daa58971bdc7d7fcaf3",
@@ -267,12 +274,28 @@
             ],
             "version": "==0.1.0"
         },
+        "black": {
+            "hashes": [
+                "sha256:1b30e59be925fafc1ee4565e5e08abef6b03fe455102883820fe5ee2e4734e0b",
+                "sha256:c2edb73a08e9e0e6f65a0e6af18b059b8b1cdd5bef997d7a0b181df93dc81539"
+            ],
+            "index": "pypi",
+            "version": "==19.10b0"
+        },
+        "bump2version": {
+            "hashes": [
+                "sha256:477f0e18a0d58e50bb3dbc9af7fcda464fd0ebfc7a6151d8888602d7153171a0",
+                "sha256:cd4f3a231305e405ed8944d8ff35bd742d9bc740ad62f483bd0ca21ce7131984"
+            ],
+            "index": "pypi",
+            "version": "==1.0.0"
+        },
         "certifi": {
             "hashes": [
-                "sha256:017c25db2a153ce562900032d5bc68e9f191e44e9a0f762f373977de9df1fbb3",
-                "sha256:25b64c7da4cd7479594d035c08c2d809eb4aab3a26e5a990ea98cc450c320f1f"
+                "sha256:1d987a998c75633c40847cc966fcf5904906c920a7f17ef374f5aa4282abd304",
+                "sha256:51fcb31174be6e6664c5f69e3e1691a2d72a1a12e90f872cbdb1567eb47b6519"
             ],
-            "version": "==2019.11.28"
+            "version": "==2020.4.5.1"
         },
         "chardet": {
             "hashes": [
@@ -281,41 +304,48 @@
             ],
             "version": "==3.0.4"
         },
+        "click": {
+            "hashes": [
+                "sha256:8a18b4ea89d8820c5d0c7da8a64b2c324b4dabb695804dbfea19b9be9d88c0cc",
+                "sha256:e345d143d80bf5ee7534056164e5e112ea5e22716bbb1ce727941f4c8b471b9a"
+            ],
+            "version": "==7.1.1"
+        },
         "coverage": {
             "hashes": [
-                "sha256:15cf13a6896048d6d947bf7d222f36e4809ab926894beb748fc9caa14605d9c3",
-                "sha256:1daa3eceed220f9fdb80d5ff950dd95112cd27f70d004c7918ca6dfc6c47054c",
-                "sha256:1e44a022500d944d42f94df76727ba3fc0a5c0b672c358b61067abb88caee7a0",
-                "sha256:25dbf1110d70bab68a74b4b9d74f30e99b177cde3388e07cc7272f2168bd1477",
-                "sha256:3230d1003eec018ad4a472d254991e34241e0bbd513e97a29727c7c2f637bd2a",
-                "sha256:3dbb72eaeea5763676a1a1efd9b427a048c97c39ed92e13336e726117d0b72bf",
-                "sha256:5012d3b8d5a500834783689a5d2292fe06ec75dc86ee1ccdad04b6f5bf231691",
-                "sha256:51bc7710b13a2ae0c726f69756cf7ffd4362f4ac36546e243136187cfcc8aa73",
-                "sha256:527b4f316e6bf7755082a783726da20671a0cc388b786a64417780b90565b987",
-                "sha256:722e4557c8039aad9592c6a4213db75da08c2cd9945320220634f637251c3894",
-                "sha256:76e2057e8ffba5472fd28a3a010431fd9e928885ff480cb278877c6e9943cc2e",
-                "sha256:77afca04240c40450c331fa796b3eab6f1e15c5ecf8bf2b8bee9706cd5452fef",
-                "sha256:7afad9835e7a651d3551eab18cbc0fdb888f0a6136169fbef0662d9cdc9987cf",
-                "sha256:9bea19ac2f08672636350f203db89382121c9c2ade85d945953ef3c8cf9d2a68",
-                "sha256:a8b8ac7876bc3598e43e2603f772d2353d9931709345ad6c1149009fd1bc81b8",
-                "sha256:b0840b45187699affd4c6588286d429cd79a99d509fe3de0f209594669bb0954",
-                "sha256:b26aaf69713e5674efbde4d728fb7124e429c9466aeaf5f4a7e9e699b12c9fe2",
-                "sha256:b63dd43f455ba878e5e9f80ba4f748c0a2156dde6e0e6e690310e24d6e8caf40",
-                "sha256:be18f4ae5a9e46edae3f329de2191747966a34a3d93046dbdf897319923923bc",
-                "sha256:c312e57847db2526bc92b9bfa78266bfbaabac3fdcd751df4d062cd4c23e46dc",
-                "sha256:c60097190fe9dc2b329a0eb03393e2e0829156a589bd732e70794c0dd804258e",
-                "sha256:c62a2143e1313944bf4a5ab34fd3b4be15367a02e9478b0ce800cb510e3bbb9d",
-                "sha256:cc1109f54a14d940b8512ee9f1c3975c181bbb200306c6d8b87d93376538782f",
-                "sha256:cd60f507c125ac0ad83f05803063bed27e50fa903b9c2cfee3f8a6867ca600fc",
-                "sha256:d513cc3db248e566e07a0da99c230aca3556d9b09ed02f420664e2da97eac301",
-                "sha256:d649dc0bcace6fcdb446ae02b98798a856593b19b637c1b9af8edadf2b150bea",
-                "sha256:d7008a6796095a79544f4da1ee49418901961c97ca9e9d44904205ff7d6aa8cb",
-                "sha256:da93027835164b8223e8e5af2cf902a4c80ed93cb0909417234f4a9df3bcd9af",
-                "sha256:e69215621707119c6baf99bda014a45b999d37602cb7043d943c76a59b05bf52",
-                "sha256:ea9525e0fef2de9208250d6c5aeeee0138921057cd67fcef90fbed49c4d62d37",
-                "sha256:fca1669d464f0c9831fd10be2eef6b86f5ebd76c724d1e0706ebdff86bb4adf0"
-            ],
-            "version": "==5.0.3"
+                "sha256:00f1d23f4336efc3b311ed0d807feb45098fc86dee1ca13b3d6768cdab187c8a",
+                "sha256:01333e1bd22c59713ba8a79f088b3955946e293114479bbfc2e37d522be03355",
+                "sha256:0cb4be7e784dcdc050fc58ef05b71aa8e89b7e6636b99967fadbdba694cf2b65",
+                "sha256:0e61d9803d5851849c24f78227939c701ced6704f337cad0a91e0972c51c1ee7",
+                "sha256:1601e480b9b99697a570cea7ef749e88123c04b92d84cedaa01e117436b4a0a9",
+                "sha256:2742c7515b9eb368718cd091bad1a1b44135cc72468c731302b3d641895b83d1",
+                "sha256:2d27a3f742c98e5c6b461ee6ef7287400a1956c11421eb574d843d9ec1f772f0",
+                "sha256:402e1744733df483b93abbf209283898e9f0d67470707e3c7516d84f48524f55",
+                "sha256:5c542d1e62eece33c306d66fe0a5c4f7f7b3c08fecc46ead86d7916684b36d6c",
+                "sha256:5f2294dbf7875b991c381e3d5af2bcc3494d836affa52b809c91697449d0eda6",
+                "sha256:6402bd2fdedabbdb63a316308142597534ea8e1895f4e7d8bf7476c5e8751fef",
+                "sha256:66460ab1599d3cf894bb6baee8c684788819b71a5dc1e8fa2ecc152e5d752019",
+                "sha256:782caea581a6e9ff75eccda79287daefd1d2631cc09d642b6ee2d6da21fc0a4e",
+                "sha256:79a3cfd6346ce6c13145731d39db47b7a7b859c0272f02cdb89a3bdcbae233a0",
+                "sha256:7a5bdad4edec57b5fb8dae7d3ee58622d626fd3a0be0dfceda162a7035885ecf",
+                "sha256:8fa0cbc7ecad630e5b0f4f35b0f6ad419246b02bc750de7ac66db92667996d24",
+                "sha256:a027ef0492ede1e03a8054e3c37b8def89a1e3c471482e9f046906ba4f2aafd2",
+                "sha256:a3f3654d5734a3ece152636aad89f58afc9213c6520062db3978239db122f03c",
+                "sha256:a82b92b04a23d3c8a581fc049228bafde988abacba397d57ce95fe95e0338ab4",
+                "sha256:acf3763ed01af8410fc36afea23707d4ea58ba7e86a8ee915dfb9ceff9ef69d0",
+                "sha256:adeb4c5b608574a3d647011af36f7586811a2c1197c861aedb548dd2453b41cd",
+                "sha256:b83835506dfc185a319031cf853fa4bb1b3974b1f913f5bb1a0f3d98bdcded04",
+                "sha256:bb28a7245de68bf29f6fb199545d072d1036a1917dca17a1e75bbb919e14ee8e",
+                "sha256:bf9cb9a9fd8891e7efd2d44deb24b86d647394b9705b744ff6f8261e6f29a730",
+                "sha256:c317eaf5ff46a34305b202e73404f55f7389ef834b8dbf4da09b9b9b37f76dd2",
+                "sha256:dbe8c6ae7534b5b024296464f387d57c13caa942f6d8e6e0346f27e509f0f768",
+                "sha256:de807ae933cfb7f0c7d9d981a053772452217df2bf38e7e6267c9cbf9545a796",
+                "sha256:dead2ddede4c7ba6cb3a721870f5141c97dc7d85a079edb4bd8d88c3ad5b20c7",
+                "sha256:dec5202bfe6f672d4511086e125db035a52b00f1648d6407cc8e526912c0353a",
+                "sha256:e1ea316102ea1e1770724db01998d1603ed921c54a86a2efcb03428d5417e489",
+                "sha256:f90bfc4ad18450c80b024036eaf91e4a246ae287701aaa88eaebebf150868052"
+            ],
+            "version": "==5.1"
         },
         "decorator": {
             "hashes": [
@@ -368,63 +398,52 @@
         },
         "jedi": {
             "hashes": [
-                "sha256:b4f4052551025c6b0b0b193b29a6ff7bdb74c52450631206c262aef9f7159ad2",
-                "sha256:d5c871cb9360b414f981e7072c52c33258d598305280fef91c6cae34739d65d5"
+                "sha256:cd60c93b71944d628ccac47df9a60fec53150de53d42dc10a7fc4b5ba6aae798",
+                "sha256:df40c97641cb943661d2db4c33c2e1ff75d491189423249e989bcea4464f3030"
             ],
-            "version": "==0.16.0"
+            "version": "==0.17.0"
         },
         "jinja2": {
             "hashes": [
-                "sha256:93187ffbc7808079673ef52771baa950426fd664d3aad1d0fa3e95644360e250",
-                "sha256:b0eaf100007721b5c16c1fc1eecb87409464edc10469ddc9a22a27a99123be49"
+                "sha256:c10142f819c2d22bdcd17548c46fa9b77cf4fda45097854c689666bf425e7484",
+                "sha256:c922560ac46888d47384de1dbdc3daaa2ea993af4b26a436dec31fa2c19ec668"
             ],
-            "version": "==2.11.1"
+            "version": "==3.0.0a1"
         },
         "markupsafe": {
             "hashes": [
-                "sha256:00bc623926325b26bb9605ae9eae8a215691f33cae5df11ca5424f06f2d1f473",
-                "sha256:09027a7803a62ca78792ad89403b1b7a73a01c8cb65909cd876f7fcebd79b161",
-                "sha256:09c4b7f37d6c648cb13f9230d847adf22f8171b1ccc4d5682398e77f40309235",
-                "sha256:1027c282dad077d0bae18be6794e6b6b8c91d58ed8a8d89a89d59693b9131db5",
-                "sha256:13d3144e1e340870b25e7b10b98d779608c02016d5184cfb9927a9f10c689f42",
-                "sha256:24982cc2533820871eba85ba648cd53d8623687ff11cbb805be4ff7b4c971aff",
-                "sha256:29872e92839765e546828bb7754a68c418d927cd064fd4708fab9fe9c8bb116b",
-                "sha256:43a55c2930bbc139570ac2452adf3d70cdbb3cfe5912c71cdce1c2c6bbd9c5d1",
-                "sha256:46c99d2de99945ec5cb54f23c8cd5689f6d7177305ebff350a58ce5f8de1669e",
-                "sha256:500d4957e52ddc3351cabf489e79c91c17f6e0899158447047588650b5e69183",
-                "sha256:535f6fc4d397c1563d08b88e485c3496cf5784e927af890fb3c3aac7f933ec66",
-                "sha256:596510de112c685489095da617b5bcbbac7dd6384aeebeda4df6025d0256a81b",
-                "sha256:62fe6c95e3ec8a7fad637b7f3d372c15ec1caa01ab47926cfdf7a75b40e0eac1",
-                "sha256:6788b695d50a51edb699cb55e35487e430fa21f1ed838122d722e0ff0ac5ba15",
-                "sha256:6dd73240d2af64df90aa7c4e7481e23825ea70af4b4922f8ede5b9e35f78a3b1",
-                "sha256:717ba8fe3ae9cc0006d7c451f0bb265ee07739daf76355d06366154ee68d221e",
-                "sha256:79855e1c5b8da654cf486b830bd42c06e8780cea587384cf6545b7d9ac013a0b",
-                "sha256:7c1699dfe0cf8ff607dbdcc1e9b9af1755371f92a68f706051cc8c37d447c905",
-                "sha256:88e5fcfb52ee7b911e8bb6d6aa2fd21fbecc674eadd44118a9cc3863f938e735",
-                "sha256:8defac2f2ccd6805ebf65f5eeb132adcf2ab57aa11fdf4c0dd5169a004710e7d",
-                "sha256:98c7086708b163d425c67c7a91bad6e466bb99d797aa64f965e9d25c12111a5e",
-                "sha256:9add70b36c5666a2ed02b43b335fe19002ee5235efd4b8a89bfcf9005bebac0d",
-                "sha256:9bf40443012702a1d2070043cb6291650a0841ece432556f784f004937f0f32c",
-                "sha256:ade5e387d2ad0d7ebf59146cc00c8044acbd863725f887353a10df825fc8ae21",
-                "sha256:b00c1de48212e4cc9603895652c5c410df699856a2853135b3967591e4beebc2",
-                "sha256:b1282f8c00509d99fef04d8ba936b156d419be841854fe901d8ae224c59f0be5",
-                "sha256:b2051432115498d3562c084a49bba65d97cf251f5a331c64a12ee7e04dacc51b",
-                "sha256:ba59edeaa2fc6114428f1637ffff42da1e311e29382d81b339c1817d37ec93c6",
-                "sha256:c8716a48d94b06bb3b2524c2b77e055fb313aeb4ea620c8dd03a105574ba704f",
-                "sha256:cd5df75523866410809ca100dc9681e301e3c27567cf498077e8551b6d20e42f",
-                "sha256:cdb132fc825c38e1aeec2c8aa9338310d29d337bebbd7baa06889d09a60a1fa2",
-                "sha256:e249096428b3ae81b08327a63a485ad0878de3fb939049038579ac0ef61e17e7",
-                "sha256:e8313f01ba26fbbe36c7be1966a7b7424942f670f38e666995b88d012765b9be"
-            ],
-            "version": "==1.1.1"
+                "sha256:06358015a4dee8ee23ae426bf885616ab3963622defd829eb45b44e3dee3515f",
+                "sha256:0b0c4fc852c5f02c6277ef3b33d23fcbe89b1b227460423e3335374da046b6db",
+                "sha256:267677fc42afed5094fc5ea1c4236bbe4b6a00fe4b08e93451e65ae9048139c7",
+                "sha256:303cb70893e2c345588fb5d5b86e0ca369f9bb56942f03064c5e3e75fa7a238a",
+                "sha256:3c9b624a0d9ed5a5093ac4edc4e823e6b125441e60ef35d36e6f4a6fdacd5054",
+                "sha256:42033e14cae1f6c86fc0c3e90d04d08ce73ac8e46ba420a0d22d545c2abd4977",
+                "sha256:4e4a99b6af7bdc0856b50020c095848ec050356a001e1f751510aef6ab14d0e0",
+                "sha256:4eb07faad54bb07427d848f31030a65a49ebb0cec0b30674f91cf1ddd456bfe4",
+                "sha256:63a7161cd8c2bc563feeda45df62f42c860dd0675e2b8da2667f25bb3c95eaba",
+                "sha256:68e0fd039b68d2945b4beb947d4023ca7f8e95b708031c345762efba214ea761",
+                "sha256:8092a63397025c2f655acd42784b2a1528339b90b987beb9253f22e8cdbb36c3",
+                "sha256:841218860683c0f2223e24756843d84cc49cccdae6765e04962607754a52d3e0",
+                "sha256:94076b2314bd2f6cfae508ad65b4d493e3a58a50112b7a2cbb6287bdbc404ae8",
+                "sha256:9d22aff1c5322e402adfb3ce40839a5056c353e711c033798cf4f02eb9f5124d",
+                "sha256:b0e4584f62b3e5f5c1a7bcefd2b52f236505e6ef032cc508caa4f4c8dc8d3af1",
+                "sha256:b1163ffc1384d242964426a8164da12dbcdbc0de18ea36e2c34b898ed38c3b45",
+                "sha256:beac28ed60c8e838301226a7a85841d0af2068eba2dcb1a58c2d32d6c05e440e",
+                "sha256:c29f096ce79c03054a1101d6e5fe6bf04b0bb489165d5e0e9653fb4fe8048ee1",
+                "sha256:c58779966d53e5f14ba393d64e2402a7926601d1ac8adeb4e83893def79d0428",
+                "sha256:cfe14b37908eaf7d5506302987228bff69e1b8e7071ccd4e70fd0283b1b47f0b",
+                "sha256:e834249c45aa9837d0753351cdca61a4b8b383cc9ad0ff2325c97ff7b69e72a6",
+                "sha256:eed1b234c4499811ee85bcefa22ef5e466e75d132502226ed29740d593316c1f"
+            ],
+            "version": "==2.0.0a1"
         },
         "mock": {
             "hashes": [
-                "sha256:2a572b715f09dd2f0a583d8aeb5bb67d7ed7a8fd31d193cf1227a99c16a67bc3",
-                "sha256:5e48d216809f6f393987ed56920305d8f3c647e6ed35407c1ff2ecb88a9e1151"
+                "sha256:3f9b2c0196c60d21838f307f5825a7b86b678cedc58ab9e50a8988187b4d81e0",
+                "sha256:dd33eb70232b6118298d516bbcecd26704689c386594f0f3c4f13867b2c56f72"
             ],
             "index": "pypi",
-            "version": "==4.0.1"
+            "version": "==4.0.2"
         },
         "more-itertools": {
             "hashes": [
@@ -464,10 +483,17 @@
         },
         "parso": {
             "hashes": [
-                "sha256:0c5659e0c6eba20636f99a04f469798dca8da279645ce5c387315b2c23912157",
-                "sha256:8515fc12cfca6ee3aa59138741fc5624d62340c97e401c74875769948d4f2995"
+                "sha256:158c140fc04112dc45bca311633ae5033c2c2a7b732fa33d0955bad8152a8dd0",
+                "sha256:908e9fae2144a076d72ae4e25539143d40b8e3eafbaeae03c1bfe226f4cdf12c"
+            ],
+            "version": "==0.7.0"
+        },
+        "pathspec": {
+            "hashes": [
+                "sha256:7d91249d21749788d07a2d0f94147accd8f845507400749ea19c1ec9054a12b0",
+                "sha256:da45173eb3a6f2a5a487efba21f050af2b41948be6ab52b6a1e3ff22bb8b7061"
             ],
-            "version": "==0.6.2"
+            "version": "==0.8.0"
         },
         "pathtools": {
             "hashes": [
@@ -499,10 +525,10 @@
         },
         "prompt-toolkit": {
             "hashes": [
-                "sha256:a402e9bf468b63314e37460b68ba68243d55b2f8c4d0192f85a019af3945050e",
-                "sha256:c93e53af97f630f12f5f62a3274e79527936ed466f038953dfa379d4941f651a"
+                "sha256:563d1a4140b63ff9dd587bda9557cffb2fe73650205ab6f4383092fb882e7dc8",
+                "sha256:df7e9e63aea609b1da3a65641ceaf5bc7d05e0a04de5bd45d05dbeffbabf9e04"
             ],
-            "version": "==3.0.3"
+            "version": "==3.0.5"
         },
         "ptyprocess": {
             "hashes": [
@@ -520,25 +546,29 @@
         },
         "pygments": {
             "hashes": [
-                "sha256:2a3fe295e54a20164a9df49c75fa58526d3be48e14aceba6d6b1e8ac0bfd6f1b",
-                "sha256:98c8aa5a9f778fcd1026a17361ddaf7330d1b7c62ae97c3bb0ae73e0b9b6b0fe"
+                "sha256:647344a061c249a3b74e230c739f434d7ea4d8b1d5f3721bc0f3558049b38f44",
+                "sha256:ff7a40b4860b727ab48fad6360eb351cc1b33cbf9b15a0f689ca5353e9463324"
             ],
-            "version": "==2.5.2"
+            "version": "==2.6.1"
+        },
+        "pygments-graphql-lexer": {
+            "git": "https://github.com/lablup/pygments-graphql-lexer.git",
+            "ref": "9b0be514959638098ad73b4d3a41b3ed025971ed"
         },
         "pyparsing": {
             "hashes": [
-                "sha256:4c830582a84fb022400b85429791bc551f1f4871c33f23e44f353119e92f969f",
-                "sha256:c342dccb5250c08d45fd6f8b4a559613ca603b57498511740e65cd11a2e7dcec"
+                "sha256:67199f0c41a9c702154efb0e7a8cc08accf830eb003b4d9fa42c4059002e2492",
+                "sha256:700d17888d441604b0bd51535908dcb297561b040819cccde647a92439db5a2a"
             ],
-            "version": "==2.4.6"
+            "version": "==3.0.0a1"
         },
         "pytest": {
             "hashes": [
-                "sha256:0d5fe9189a148acc3c3eb2ac8e1ac0742cb7618c084f3d228baaec0c254b318d",
-                "sha256:ff615c761e25eb25df19edddc0b970302d2a9091fbce0e7213298d85fb61fef6"
+                "sha256:0e5b30f5cb04e887b91b1ee519fa3d89049595f428c1db76e73bd7f17b09b172",
+                "sha256:84dde37075b8805f3d1f392cc47e38a0e59518fb46a431cfdaf7cf1ce805f970"
             ],
             "index": "pypi",
-            "version": "==5.3.5"
+            "version": "==5.4.1"
         },
         "pytest-aiohttp": {
             "hashes": [
@@ -570,6 +600,32 @@
             ],
             "version": "==2019.3"
         },
+        "regex": {
+            "hashes": [
+                "sha256:08119f707f0ebf2da60d2f24c2f39ca616277bb67ef6c92b72cbf90cbe3a556b",
+                "sha256:0ce9537396d8f556bcfc317c65b6a0705320701e5ce511f05fc04421ba05b8a8",
+                "sha256:1cbe0fa0b7f673400eb29e9ef41d4f53638f65f9a2143854de6b1ce2899185c3",
+                "sha256:2294f8b70e058a2553cd009df003a20802ef75b3c629506be20687df0908177e",
+                "sha256:23069d9c07e115537f37270d1d5faea3e0bdded8279081c4d4d607a2ad393683",
+                "sha256:24f4f4062eb16c5bbfff6a22312e8eab92c2c99c51a02e39b4eae54ce8255cd1",
+                "sha256:295badf61a51add2d428a46b8580309c520d8b26e769868b922750cf3ce67142",
+                "sha256:2a3bf8b48f8e37c3a40bb3f854bf0121c194e69a650b209628d951190b862de3",
+                "sha256:4385f12aa289d79419fede43f979e372f527892ac44a541b5446617e4406c468",
+                "sha256:5635cd1ed0a12b4c42cce18a8d2fb53ff13ff537f09de5fd791e97de27b6400e",
+                "sha256:5bfed051dbff32fd8945eccca70f5e22b55e4148d2a8a45141a3b053d6455ae3",
+                "sha256:7e1037073b1b7053ee74c3c6c0ada80f3501ec29d5f46e42669378eae6d4405a",
+                "sha256:90742c6ff121a9c5b261b9b215cb476eea97df98ea82037ec8ac95d1be7a034f",
+                "sha256:a58dd45cb865be0ce1d5ecc4cfc85cd8c6867bea66733623e54bd95131f473b6",
+                "sha256:c087bff162158536387c53647411db09b6ee3f9603c334c90943e97b1052a156",
+                "sha256:c162a21e0da33eb3d31a3ac17a51db5e634fc347f650d271f0305d96601dc15b",
+                "sha256:c9423a150d3a4fc0f3f2aae897a59919acd293f4cb397429b120a5fcd96ea3db",
+                "sha256:ccccdd84912875e34c5ad2d06e1989d890d43af6c2242c6fcfa51556997af6cd",
+                "sha256:e91ba11da11cf770f389e47c3f5c30473e6d85e06d7fd9dcba0017d2867aab4a",
+                "sha256:ea4adf02d23b437684cd388d557bf76e3afa72f7fed5bbc013482cc00c816948",
+                "sha256:fb95debbd1a824b2c4376932f2216cc186912e389bdb0e27147778cf6acb3f89"
+            ],
+            "version": "==2020.4.4"
+        },
         "requests": {
             "hashes": [
                 "sha256:43999036bfa82904b6af1d99e4882b560e5e2c68e5c4b0aa03b655f3d7d73fee",
@@ -593,11 +649,11 @@
         },
         "sphinx": {
             "hashes": [
-                "sha256:b4c750d546ab6d7e05bdff6ac24db8ae3e8b8253a3569b754e445110a0a12b66",
-                "sha256:fc312670b56cb54920d6cc2ced455a22a547910de10b3142276495ced49231cb"
+                "sha256:3145d87d0962366d4c5264c39094eae3f5788d01d4b1a12294051bfe4271d91b",
+                "sha256:d7c6e72c6aa229caf96af82f60a0d286a1521d42496c226fe37f5a75dcfe2941"
             ],
             "index": "pypi",
-            "version": "==2.4.4"
+            "version": "==3.0.2"
         },
         "sphinxcontrib-applehelp": {
             "hashes": [
@@ -641,6 +697,13 @@
             ],
             "version": "==1.1.4"
         },
+        "toml": {
+            "hashes": [
+                "sha256:229f81c57791a41d65e399fc06bf0848bab550a9dfd5ed66df18ce5f05e73d5c",
+                "sha256:235682dd292d5899d361a811df37e04a8828a5b1da3115886b73cf81ebc9100e"
+            ],
+            "version": "==0.10.0"
+        },
         "traitlets": {
             "hashes": [
                 "sha256:70b4c6a1d9019d7b4f6846832288f86998aa3b9207c6821f3578a6a6a467fe44",
@@ -648,12 +711,46 @@
             ],
             "version": "==4.3.3"
         },
+        "typed-ast": {
+            "hashes": [
+                "sha256:0666aa36131496aed8f7be0410ff974562ab7eeac11ef351def9ea6fa28f6355",
+                "sha256:0c2c07682d61a629b68433afb159376e24e5b2fd4641d35424e462169c0a7919",
+                "sha256:249862707802d40f7f29f6e1aad8d84b5aa9e44552d2cc17384b209f091276aa",
+                "sha256:24995c843eb0ad11a4527b026b4dde3da70e1f2d8806c99b7b4a7cf491612652",
+                "sha256:269151951236b0f9a6f04015a9004084a5ab0d5f19b57de779f908621e7d8b75",
+                "sha256:4083861b0aa07990b619bd7ddc365eb7fa4b817e99cf5f8d9cf21a42780f6e01",
+                "sha256:498b0f36cc7054c1fead3d7fc59d2150f4d5c6c56ba7fb150c013fbc683a8d2d",
+                "sha256:4e3e5da80ccbebfff202a67bf900d081906c358ccc3d5e3c8aea42fdfdfd51c1",
+                "sha256:6daac9731f172c2a22ade6ed0c00197ee7cc1221aa84cfdf9c31defeb059a907",
+                "sha256:715ff2f2df46121071622063fc7543d9b1fd19ebfc4f5c8895af64a77a8c852c",
+                "sha256:73d785a950fc82dd2a25897d525d003f6378d1cb23ab305578394694202a58c3",
+                "sha256:8c8aaad94455178e3187ab22c8b01a3837f8ee50e09cf31f1ba129eb293ec30b",
+                "sha256:8ce678dbaf790dbdb3eba24056d5364fb45944f33553dd5869b7580cdbb83614",
+                "sha256:aaee9905aee35ba5905cfb3c62f3e83b3bec7b39413f0a7f19be4e547ea01ebb",
+                "sha256:bcd3b13b56ea479b3650b82cabd6b5343a625b0ced5429e4ccad28a8973f301b",
+                "sha256:c9e348e02e4d2b4a8b2eedb48210430658df6951fa484e59de33ff773fbd4b41",
+                "sha256:d205b1b46085271b4e15f670058ce182bd1199e56b317bf2ec004b6a44f911f6",
+                "sha256:d43943ef777f9a1c42bf4e552ba23ac77a6351de620aa9acf64ad54933ad4d34",
+                "sha256:d5d33e9e7af3b34a40dc05f498939f0ebf187f07c385fd58d591c533ad8562fe",
+                "sha256:fc0fea399acb12edbf8a628ba8d2312f583bdbdb3335635db062fa98cf71fca4",
+                "sha256:fe460b922ec15dd205595c9b5b99e2f056fd98ae8f9f56b888e7a17dc2b757e7"
+            ],
+            "version": "==1.4.1"
+        },
+        "typing-extensions": {
+            "hashes": [
+                "sha256:6e95524d8a547a91e08f404ae485bbb71962de46967e1b71a0cb89af24e761c5",
+                "sha256:79ee589a3caca649a9bfd2a8de4709837400dfa00b6cc81962a1e6a1815969ae",
+                "sha256:f8d2bd89d25bc39dabe7d23df520442fa1d8969b82544370e03d88b5a591c392"
+            ],
+            "version": "==3.7.4.2"
+        },
         "urllib3": {
             "hashes": [
-                "sha256:2f3db8b19923a873b3e5256dc9c2dedfa883e33d87c690d9c7913e1f40673cdc",
-                "sha256:87716c2d2a7121198ebcb7ce7cccf6ce5e9ba539041cfbaeecfb641dc0bf6acc"
+                "sha256:3018294ebefce6572a474f0604c2021e33b3fd8006ecd11d62107a5d2a963527",
+                "sha256:88206b0eb87e6d677d424843ac5209e3fb9d0190d0ee169599165ec25e9d9115"
             ],
-            "version": "==1.25.8"
+            "version": "==1.25.9"
         },
         "watchdog": {
             "hashes": [
@@ -664,10 +761,10 @@
         },
         "wcwidth": {
             "hashes": [
-                "sha256:8fd29383f539be45b20bd4df0dc29c20ba48654a41e661925e612311e9f3c603",
-                "sha256:f28b3e8a6483e5d49e7f8949ac1a78314e740333ae305b4ba5defd3e74fb37a8"
+                "sha256:cafe2186b3c009a04067022ce1dcd79cb38d8d65ee4f4791b8888d6599d1bbe1",
+                "sha256:ee73862862a156bf77ff92b09034fc4825dd3af9cf81bc5b360668d425f3c5f1"
             ],
-            "version": "==0.1.8"
+            "version": "==0.1.9"
         },
         "yarl": {
             "hashes": [
diff --git a/kofi/__init__.py b/kofi/__init__.py
index e24faa2..6a72f58 100644
--- a/kofi/__init__.py
+++ b/kofi/__init__.py
@@ -1,5 +1,5 @@
 """Top-level package for KoFi."""
 
 __author__ = """Leonardo Barcaroli"""
-__email__ = 'leonardo.barcaroli@prima.it'
-__version__ = '0.1.0'
+__email__ = "leonardo.barcaroli@prima.it"
+__version__ = "0.1.0"
diff --git a/setup.cfg b/setup.cfg
index 3960af9..27bc39d 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -2,14 +2,19 @@
 current_version = 0.1.0
 commit = True
 tag = True
+sign_tag = True
 
 [bumpversion:file:setup.py]
-search = version='{current_version}'
-replace = version='{new_version}'
+search = version="{current_version}"
+replace = version="{new_version}"
 
 [bumpversion:file:kofi/__init__.py]
-search = __version__ = '{current_version}'
-replace = __version__ = '{new_version}'
+search = __version__ = "{current_version}"
+replace = __version__ = "{new_version}"
+
+[bumpversion:file:Makefile]
+search = VERSION := {current_version}
+replace = VERSION := {new_version}
 
 [bdist_wheel]
 universal = 1