Make service profiles default to rabbitmq_node_ips

Make service profiles default to rabbitmq_node_ips

Instead of hard-coded yaml aliases in t-h-t, make each service
profile that requires rabbit default to the list of rabbit ips.

Note this could still be extended in future to e.g enable per
service rabbit clusters, but the default is to lookup the
hiera which should be logically equivalent to current t-h-t.

Change-Id: Ie53c93456529420588eb1927703ea91b54095d87
Partially-Implements: blueprint custom-roles