docs(contributing.md): add docs for "ci" commit type/scope

IgorMinar · rkirov · commit c4c43f5a77b5 · 2016-01-26T14:55:42.000-08:00
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -180,7 +180,8 @@ Must be one of the following:
 * **refactor**: A code change that neither fixes a bug nor adds a feature
 * **perf**: A code change that improves performance
 * **test**: Adding missing tests or correcting existing tests
-* **build** Changes that affect the build system, CI configuration or external dependencies (example scopes: gulp, broccoli, npm)
+* **build**: Changes that affect the build system, CI configuration or external dependencies (example scopes: gulp, broccoli, npm)
+* **ci**: Any changes to our CI configuration files and scripts (Travis, Circle CI, BrowserStack, SauceLabs)
 * **chore**: Other changes that don't modify `src` or `test` files
 
 ### Scope
