The service catalog can now have the cinder endpoint x.x.x.x:8776 with
service_type volume, without needing to specify a version in the
endpoint. Keystone will do discovery of the root / GET of the Cinder API
to discover the versions that can be talked to.
This also provides backwards compatibility for the previous solution of
having v1 enabled on service_type volume and v2 on service_type
volumev2.
Change-Id: Id0347f8370dbc8fd7fa8096cd5859e10b0c5d67c