* Switch to using sphinx-build
* Fix docs warnings
* Remove test-requirement and fold in requirements, we don't need two
files for this docu only repo.
* Remove unused requirement pytz.
* Update doc requirements
* Remove cruft from setup.cfg and doc/source/conf.py
* Switch to Python3
Change-Id: Iae32f7daa656fca6ae80a750746215fe80d4a0d6