Raising commit message quality

Author: raphaelstolt

.gitattributes

@@ -4,6 +4,7 @@
 .gitattributes export-ignore
 .github/ export-ignore
 .gitignore export-ignore
+.gitmessage export-ignore
 .php_cs export-ignore
 .travis.yml export-ignore
 bin/increment-application-version export-ignore

.github/CONTRIBUTING.md

@@ -6,4 +6,6 @@ Thanks for considering to contribute to the `LeanPackageValidator`. Please follo
 
 - Ensure the coding standard compliance before committing or opening pull requests by running `composer cs-fix` in the root directory of this repository.
 
+- Use the provided [commit message template](../.gitmessage), which follows the [rules](http://chris.beams.io/posts/git-commit/) described by Chris Beams, and configure it via `composer configure-commit-template` prior to committing.
+
 - All upstreamed contributions __MUST__ use [feature / topic branches](https://git-scm.com/book/en/v2/Git-Branching-Branching-Workflows) to ease their merging.

.gitmessage

@@ -0,0 +1,11 @@
+Subject line
+
+# - Capitalise the subject line and do not end it with a period
+# - Use the imperative mood in the subject line
+# - Summarise changes in around 50 (soft limit, hard limit at 69)
+#   characters or less in the subject line
+# - Separate subject line from body with a blank line
+Optional subject body
+# - Capitalise the subject body
+# - Use the subject body to explain what and why vs. how
+# - Wrap the subject body at 72 characters

composer.json

@@ -28,7 +28,8 @@
     "bin": ["bin/lean-package-validator"],
     "scripts": {
         "test": "phpunit",
-        "cs-fix": "php-cs-fixer fix . -vv || true"
+        "cs-fix": "php-cs-fixer fix . -vv || true",
+        "configure-commit-template": "git config --add commit.template .gitmessage"
     },
     "require-dev": {
         "phpunit/phpunit": "^4.8 || ^5.0",