Updated openstack/openstack
Project: openstack-dev/pbr  6ffff7c95706e3a39e82fa0362e825aab21cbb26
null
Factor run_cmd out of the base class.

I want to reuse this for factoring out some fixtures, so make it
reusable.

Change-Id: I7035a514adf889a8ebaadff9ae873341804fe099