Merge branch 'remove-git-commit-attribute' into 'master'

Remove unused attr_accessor from Gitlab::Git::Commit

See merge request !12311

lib/gitlab/git/commit.rb

@@ -4,7 +4,7 @@ module Gitlab
     class Commit
       include Gitlab::EncodingHelper
 
-      attr_accessor :raw_commit, :head, :refs
+      attr_accessor :raw_commit, :head
 
       SERIALIZE_KEYS = [
         :id, :message, :parent_ids,