Add plugin queue to all_queues.yml

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/workers/all_queues.yml

@@ -84,6 +84,7 @@
 - new_note
 - pages
 - pages_domain_verification
+- plugin
 - post_receive
 - process_commit
 - project_cache

spec/workers/plugin_worker_spec.rb

@@ -21,7 +21,7 @@ describe PluginWorker do
       allow(Gitlab::Plugin).to receive(:execute).with(filename, data).and_raise('Permission denied')
-      expect { subject.perform(filename, data) }.to_not raise_error
+      expect { subject.perform(filename, data) }.not_to raise_error
     end
   end
 end