Updated openstack/openstack
Project: openstack/taskflow  543b6a06f7dc64b6ef604d52cb13d61cf9bc1f63

Link bug in requirements so people understand why pbr is listed

To make it more obvious why pbr is the first requirement in the file/s
add a link to the bug that caused this requirement to be re-added so
that for future prosperity/generations... it is known.

Change-Id: I11b23675cc379934e83b237bc30ca6baa0a87751