Updated openstack/openstack
Project: openstack-dev/pbr  d6bd32eea46447626f338cfd088e34ce6e92ce55

Permit pre-release versions with git metadata

This is implied by the example and seems necessary for doing automated
generation of pre-release versions.

Change-Id: I8d4ceec200fac7982f2dafa7f8f1a8abfd4b0f83