Task-based deployment instead of role-based deployment
results in faster deployment, but requires better
management of task dependencies. RabbitMQ tasks are
now better tuned to ensure detached RabbitMQ is ready
before deployment starts.
Other minor changes:
Added primary role to standalone-rabbitmq role
Updated hiera override for new role name
Depends-On: I5e835a448ad0d77f0f82630273e15c00261cfb82
Change-Id: I1c8ec11a1507b48237641da7c4bac036745859cb
Partial-Bug: #1553239