We had 14.0.0 for Newton but weren't specifying these
for Liberty, Mitaka or Ocata release notes.
The Liberty tag starts at 12.0.1 since that's the first
tagged release in the stable/liberty branch where we
started using reno:
5207013fddd296d062d1f375dfafde382a98f92d
12.0.0 release note are in the wiki:
https://wiki.openstack.org/wiki/ReleaseNotes/Liberty
Change-Id: Iebb7d487e8d70f1e1ee5dc6519d3ad3ffcb385bd
Matt Riedemann