This change ensures that the RabbitMQ ServerName is being set to
the **ansible_hostname** fact. This ensures the RabbitMQ server
has an appropriate server name which is compliant to the RFC.
Change-Id: I1f6a161b3af8fd0edd677ac1c3f396e6e8b5d02e
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>