Updated openstack/openstack
Project: openstack-dev/pbr  8494418e715ced5cd519224249794cc6f5fa241f
null
make pbr use hacking directly

Remove flake8 from pbr's requirements file, we should be requiring
hacking instead, and let hacking pull in flake8.

Change-Id: I6e7135a07e3ca6b9e26fcc9623b1434ecba1444f