Fix bug where a push would only create cross references from the first commit.

app/services/git_push_service.rb

@@ -79,7 +79,7 @@ class GitPushService
 
     authors = Hash.new do |hash, commit|
       email = commit.author_email
-      return hash[email] if hash.has_key?(email)
+      next hash[email] if hash.has_key?(email)
 
       hash[email] = commit_user(commit)
     end

lib/gitlab/reference_extractor.rb

@@ -27,7 +27,7 @@ module Gitlab
     def references
       @references ||= Hash.new do |references, type|
         type = type.to_sym
-        return references[type] if references.has_key?(type)
+        next references[type] if references.has_key?(type)
 
         references[type] = pipeline_result(type)
       end