Merge branch 'dont-fail-danger-with-emojis' into 'master'

Don't fail the pipeline when a colon-emoji is used

See merge request gitlab-org/gitlab-ce!29291

danger/commit_messages/Dangerfile

@@ -163,10 +163,10 @@ def lint_commit(commit)
   end
 
   if emoji_checker.includes_emoji?(commit.message)
-    fail_commit(
+    warn_commit(
       commit,
       'Avoid the use of Markdown Emoji such as `:+1:`. ' \
-        'These add no value to the commit message, ' \
+        'These add limited value to the commit message, ' \
         'and are displayed as plain text outside of GitLab'
     )