Pass the DOCKER_* env vars when running docker
Pass the DOCKER_* env vars when running docker

We should always pass the `DOCKER_*` env vars to all the `docker`
commands that are executed in the various scripts as those variables may
contain the access data for the docker daemon.

Change-Id: Ie719f451350e6ea35cb22d97a8f090ad81fa8141

openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,dprince/tripleo-heat-templates,openstack/tripleo-heat-templates