In prep-apply we're assuing virtualenv which is not there. Now
that the nodes don't have it by default, this breaks. Add it.
Change-Id: I07a392f5bcbf4d5f04d8812d5c712d2fcc60747b
These use legacy-base, which sucks, but what sucks even more is
that they are in openstack-zuul-jobs, which makes them extra
awkward to try to adjust.
Change-Id: I87b3d56de41f0ba5658c1240ddfc7ecf1c3c43af