Cleanup bindep
Cleanup bindep

The repo is now python3 only, remove python2 devel package
(python-dev).

Remove tags for precise, it's not supported.

All current RPM distros have python3-devel, so use it.

Change-Id: Ibf4a712d90d7a2a9483e42952174d20630af2fb6

openstack/openstackdocstheme,openstack/openstackdocstheme,openstack/openstackdocstheme,openstack/openstackdocstheme