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: I9947bc813182bc090d96a911fd5ae2b3b92bb740
Marc Gariepy