containerized deployment (OSP): "containers" var is undefined when using tags

[asyedham]

When we are running the stockpile.yml playbook in ci_tesh.sh it will not run the tasks for containerized deployment (because containers var is undefined)
example:
https://github.com/cloud-bulldozer/stockpile/blob/master/roles/openstack_rabbitmq/tasks/main.yml#L18 as the "containers" var is set as a fact in roles/openstack_common and the current ci_tesh.sh runs each role using a tag. So the "containers var" is set as fact only for that iteration and for the next iteration(i.e tag) containers var is undefined.