port changes from cloudalchemy repositories (#36)

- drop ansible 2.3
- test on ansible 2.7
- use tox
- create a new [minor] release.

.travis.yml

@@ -1,16 +1,17 @@
+---
 sudo: required
 language: python
 cache: pip
 services:
   - docker
 env:
-  - ANSIBLE='ansible>=2.3.0,<2.4.0'
-  - ANSIBLE='ansible>=2.4.0,<2.5.0'
-  - ANSIBLE='ansible>=2.5.0,<2.6.0'
+  - ANSIBLE=2.5
+  - ANSIBLE=2.6
+  - ANSIBLE=2.7
 install:
-  - pip install ${ANSIBLE} 'ansible-lint>=3.4.15' 'molecule>=2.13.0' docker git-semver 'testinfra>=1.7.0'
+  - pip install tox-travis git-semver
 script:
-  - molecule test --all
+  - tox
 deploy:
   provider: script
   skip_cleanup: true

test-requirements.txt

@@ -0,0 +1,6 @@
+ansible-lint>=3.4.0
+docker
+jmespath
+molecule>=2.15.0
+pytest==3.9.3
+testinfra>=1.7.0

tox.ini

@@ -0,0 +1,20 @@
+[tox]
+minversion = 1.8
+envlist = py{27}-ansible{25,26,27}
+skipsdist = true
+
+[travis:env]
+ANSIBLE=
+  2.5: ansible25
+  2.6: ansible26
+  2.7: ansible27
+
+[testenv]
+passenv = *
+deps =
+    -rtest-requirements.txt
+    ansible25: ansible<2.6
+    ansible26: ansible<2.7
+    ansible27: ansible<2.8
+commands =
+    {posargs:molecule test --all --destroy always}