add oslo and infra from git to the upgrade

to make grenade work like havana master we need to bring in infra
and oslo repositories from upstream git and apply global
requirements to all the repositories.

Update functions file from devstack.

Attempt to uninstall oslo.config first, to deal with weird pip
issues where 1.1.1 is still installed, but 1.2.x from git is in
the easy repo files, and nova-manage explodes.

Change-Id: I310d40a0adc9355eea91e79598bf867ad6818b79