Port fact caching system to rabbitmq

* Purge all references to zmq also
* New setting to control the queue it works on

awx/settings/defaults.py

@@ -797,6 +797,8 @@ ACTIVITY_STREAM_ENABLED_FOR_INVENTORY_SYNC = False
 INTERNAL_API_URL = 'http://127.0.0.1:%s' % DEVSERVER_DEFAULT_PORT
 
 CALLBACK_QUEUE = "callback_tasks"
+FACT_QUEUE = "facts"
+
 SCHEDULER_QUEUE = "scheduler"
 
 TASK_COMMAND_PORT = 6559