* Mention python 3 support in setup.py
* Build universal (py2 and py3 compatible) wheels
* Mention Python 3.3+ support in docs
* we work on python 3.6 too
* stop conditionally pinning mock version in acme
* stop conditionally pinning mock version in certbot
* stop conditionally pinning mock version in apache
* stop conditionally pinning mock version in nginx
* stop conditionally pinning mock version in letshelp
* stop conditionally pinning mock version in compatibility-test
