Merge branch 'winh-frontend-ci-roulette' into 'master'

Add .gitlab/ci/frontend.gitlab-ci.yml to frontend review roulette

See merge request gitlab-org/gitlab-ce!32466

lib/gitlab/danger/helper.rb

@@ -110,7 +110,8 @@ module Gitlab
           karma\.config\.js |
           webpack\.config\.js |
           package\.json |
-          yarn\.lock
+          yarn\.lock |
+          \.gitlab/ci/frontend\.gitlab-ci\.yml
         )\z}x => :frontend,
 
         %r{\A(ee/)?db/(?!fixtures)[^/]+} => :database,