Description of problem: python-novaclient currently packages the latest upstream tag, 2.17.0, which does not include the server group commands that were added relatively recently. Ideally a new upstream client tag should be created encompassing these changes and be packaged accordingly. See also: https://ask.openstack.org/en/question/30433/why-are-nova-server-group-apis-missing-in-rdo-icehouse-installation/?answer=30492#post-id-30492
Server group commands are available in python-novaclient-2.17.0-2.