spec file for pulp_openstack

This builds the following:

pulp-openstack-admin-extensions
pulp-openstack-plugins
python-pulp-openstack-common

You will need to pull down python-keystoneclient and python-glanceclient. Both
are available from RDO.

This patch requires a `tito init` after merging. The %changelog will then be populated.
I don't think this is necessary, since pulp_openstack doesn't have its own wsgi app.