Fix operation on clouds with availability-zones

In a cloud with AZs, you can get multiple entries back from the service
catalog - one for each AZ and then one that is AZ agnostic that's tied
to the region. If the region_name is plumbed all the way through, this
works as intended.

Change-Id: I3b365ea306e8111fc80830672ae8080a5d1dc8e0
Put pbr and six first in requirements list

Each of them have scenarios where it's important that they install
first.

Change-Id: Ia9fff6e94651693f9fa74ca676771b19144bcd8b
Merge "Fix operation on clouds with availability-zones"
Merge "Put pbr and six first in requirements list"