We need to have a newer facter installed in order to get an updated fact for piston cloud

This moves the apt configuration into the setup.pp run, so we can get the
backport source added early which will enable us to install the latest facter
from the backports repository.

Change-Id: I8ccf1a0445dea72f1b94be08484f33e648439ec1
Merge remote-tracking branch 'micah/bug/2942' into develop