Added Versions to the client-side models
Added Versions to the client-side models

Versions would be useful for determining whether an API is usable before
invocation happens.

openstack/python-senlinclient,stackforge/python-senlinclient,tengqm/python-senlinclient,stackforge/python-senlinclient,openstack/python-senlinclient,tengqm/python-senlinclient