Enhance .travis.yml formatting

.travis.yml

@@ -1,36 +1,36 @@
 language: node_js
 node_js:
-- '4.4'
+  - "6"
 
 script:
-- gulp lint
-- gulp build
-- gulp package
-- gulp bower
+  - gulp lint
+  - gulp build
+  - gulp package
+  - gulp bower
 
-deploy:
-# Creates a tag containing dist files and bower.json
-# Requires GITHUB_AUTH_TOKEN and GITHUB_AUTH_EMAIL environment variables
-# IMPORTANT: the script has to be set executable in the Git repository (error 127)
+# IMPORTANT: scripts require GITHUB_AUTH_TOKEN and GITHUB_AUTH_EMAIL environment variables
+# IMPORTANT: scripts has to be set executables in the Git repository (error 127)
 # https://github.com/travis-ci/travis-ci/issues/5538#issuecomment-225025939
 # http://stackoverflow.com/a/15572639
-- provider: script
-  script: ./scripts/release.sh
-  skip_cleanup: true
-  on:
-    branch: release
-- provider: releases
-  api_key: $GITHUB_AUTH_TOKEN
-  file:
-  - "./dist/chartjs-plugin-deferred.js"
-  - "./dist/chartjs-plugin-deferred.min.js"
-  - "./dist/chartjs-plugin-deferred.zip"
-  skip_cleanup: true
-  on:
-    tags: true
-- provider: npm
-  email: $NPM_AUTH_EMAIL
-  api_key: $NPM_AUTH_TOKEN
-  skip_cleanup: true
-  on:
-    tags: true
+
+deploy:
+  - provider: script
+    script: ./scripts/release.sh
+    skip_cleanup: true
+    on:
+      branch: release
+  - provider: releases
+    api_key: $GITHUB_AUTH_TOKEN
+    file:
+      - "./dist/chartjs-plugin-deferred.js"
+      - "./dist/chartjs-plugin-deferred.min.js"
+      - "./dist/chartjs-plugin-deferred.zip"
+    skip_cleanup: true
+    on:
+      tags: true
+  - provider: npm
+    email: $NPM_AUTH_EMAIL
+    api_key: $NPM_AUTH_TOKEN
+    skip_cleanup: true
+    on:
+      tags: true