Open Stack

I had originally been planning to wait for the cycle-trailing
projects to finish Rocky before updating the release jobs to use
the python3 versions. However, Sean reminded me today that we
extended the deadline for cycle-trailing projects to 2 months from
now, and I don't think we want to wait that long to change the other
projects.

I have prepared a patch [1] to switch all official python projects
to the python3 publishing job right away, so we have time to resolve
any issues that causes before the first milestone of the Stein
cycle.

As I mentioned before, when that patch lands, it will add a new
check job to all projects so that if any packaging-related files
are changed the ability to package the project is tested. Let me
know if you run into any difficulties.

Doug

[1] https://review.openstack.org/598323