Update version of python-pbr used by Delorean
Update version of python-pbr used by Delorean

Some projects are requiring newer versions of python-pbr, so we
will use the Koji build until it is available in an official repo.

Change-Id: I379301df5fa7620d939853080fc904479895b416

openstack-packages/DLRN,openstack-packages/delorean,openstack-packages/DLRN,openstack-packages/delorean