This patch introduces the qdrouterd role for deployment as
a direct messaging bus for oslo.messaging rpc communications.
The qdrouterd is deployed as infrastructure in a manner similar
to the rabbitmq server.
This patch:
* Add to role requirements
* Add to inventory
* Add to playbooks
* Add experimental aio job
Change-Id: If9eed3d5848939eac005651336a1305433d96dbf