- Add web hook queue code back in. We'll remove it and turn it off after this CL goes to prod

- Make notification lookup always be by repo and its UUID, rather than the internal DB ID
- Add the init script for the notification worker

conf/init/notificationworker/run

@@ -0,0 +1,8 @@
+#! /bin/bash
+
+echo 'Starting notification worker'
+
+cd /
+venv/bin/python -m workers.notificationworker
+
+echo 'Notification worker exited'