Implement functional testing gating for rabbitmq container

We need to get started on functional testing. To prove that containers can be run in the OpenStack gate, we need a functional test gate job added for Kolla to the OpenStack project infrastructure.

This involves modifying the repo at http://github.com/openstack-infra/project-config and adding the ability to run a shell script or some other test infrastructure that contains code to launch the containers and run either custom test cases or tempest. I'd like to start simple with a basic rabbitmq container launch and functional test case.

Reference of discussion of how to tackle this blueprint is in this log:
http://eavesdrop.openstack.org/irclogs/%23openstack-infra/%23openstack-infra.2015-02-10.log (search for sdake/jeblair discussion)