Merge branch '6.0' into 6.1

* 6.0:
  update CI intro

Author: javiereguiluz

contributing/code/tests.rst

@@ -3,7 +3,7 @@
 Running Symfony Tests
 =====================
 
-The Symfony project uses a third-party service which automatically runs tests
+The Symfony project uses a CI (Continuous Integration) service which automatically runs tests
 for any submitted :doc:`patch <pull_requests>`. If the new code breaks any test,
 the pull request will show an error message with a link to the full error details.