Make a few cleanups:
- Remove python 2.7 stanza from setup.py
- Add requires on python >= 3.6 to setup.cfg so that pypi and pip
know about the requirement
- Update classifiers
Change-Id: I5558143efb0e70ce1428a13d5496cc21ead6526a
Use cookiecutter (https://git.openstack.org/openstack-dev/cookiecutter)
to generate config for tox so we can generate docs, run pep8, etc.
Also move CONTRIBUTING.rst to the root of the repository in keeping
with what seems to be the standard location. This move allows us to
easily generate the docs. Also include a tiny fix to allow pep8 to
run cleanly.
Change-Id: Ifbfc6d85c7b02bf4ab989974b491a3a1ae6f0900