Added rabbitmqadmin and enabled management plugin

Useful for debugging issues with rabbit, and inspecting the queues.

* Enabled the management plugin
* Added administrator tag to the user.  This provides access to the
  management interface.
* Wrote integration tests to confirm this setup.
Merge pull request #163 from blueboxgroup/blueboxgroup/rabbitmq-management-cli

Added rabbitmqadmin and enabled management plugin