This repo is now testing only with Python 3, so let's make
a few cleanups:
- Remove python 2.7 stanza from setup.py
- Remove obsolete sections from setup.cfg
- Enable warnings for sphinx-build
- Cleanup doc/source/conf.py to remove now obsolete content.
Change-Id: I58849f8ace219a1d23540932c9481f50fc98225c
openstack-dev was decomissioned this night in https://review.openstack.org/621258
Update openstack-dev to openstack-discuss
Change-Id: Idd85f6b91dfb582a7d944315e2057e9760c20586