This allows us to use versionless endpoints for keystone in the
configuration files and furthermore, we won't depend on a specific
keystone version, as is the case today.
Change-Id: I124c0ea2d9403d6b530b33f18896c4e7bf4eabb5
Depends-On: I35f1c9dcd20017b9c442b04c142e46cad4d15eb4