Update version for Liberty
Update version for Liberty

Update the version for Liberty, switching from date-based versioning
to pre-versioning using SemVer. See
http://lists.openstack.org/pipermail/openstack-dev/2015-May/065211.html
and
http://lists.openstack.org/pipermail/openstack-dev/2015-June/067082.html
for details.

Change-Id: I1ef1e710924c208e7360f2258117d4f80b69442a

openstack/sahara-image-elements,bigfootproject/sahara-image-elements,crobby/sahara-image-elements,uladz/sahara-image-elements,uladz/sahara-image-elements,openstack/sahara-image-elements,crobby/sahara-image-elements,bigfootproject/sahara-image-elements