This introduces oslo.messaging variables that define the RPC and
Notify transports for the OpenStack services. These parameters replace
the rabbitmq values and are used to generate the messaging
transport_url for the service. The association of the messaging
backend server to the oslo.messaging services will then be transparent
to the masakari service.
This patch:
* Add oslo.messaging variables for RPC and Notify to defaults
* Update transport_url generation in conf
* Add oslo.messaging to tests inventory and update tests
* Install extra packages for optional drivers
Change-Id: I127ce216cfb7b4d5755b8f0a68406bbd251fbdd2