This ansible module for docker-compose allows for idempotency. I have
submitted a pull request upstream to ansible-modules-extra to include
this new module. When/if the module is accepted upstream if can be
removed from the local module library.

The two playbooks have been updated to use this module. The database
data container does not support idempotency due to the fact that it
exists instead of sleeps. Therefore each time `docker-compose up` is
called, it will start the container and register a change. The
message-broker does not have this issue and will remain unchanged even
repeatedly running these playbooks.

Due to the use of a special branch of docker-compose provided by sdake,
this module requires at least docker-compose==1.2.0rc1

Change-Id: If1644eaa3bff0c2a007fa2d479a95bea941945f6