Switch os-cloud-config to using python{,3}-jobs

Now that the python33 job for os-cloud-config can vote, add it to
the gate by way of switching os-cloud-config to making use of the
python-jobs and python3-jobs templates.

Change-Id: I71045243e35045483c3c8163f12f7ae6238d00f4
Merge "Switch os-cloud-config to using python{,3}-jobs"