only run on openstack gate projects

we only want to run on things we consider the "integrated" gate,
however, that's kind of a nebulus definition. Today a reasonable
heuristic is if we are running the tempest full job, so use that.

This check could be enhanced in the future.

Change-Id: Iad36d330f8f6db3bbaa0c54a0c8e70b0e01a17b6