Dropping 3.3 makes sense, as does deprecating 3.4

The only thing I suggest/request is a webpage (and possibly txtfile in the source) that lists the supported Python versions.  When people runs into issues, finding this info quickly is just so useful.

e.g.

Version Python2 Python3

Twisted 17.3   2.x+ 3.x+

I helped build the first version of a similar grid for sqlalchemy - http://www.sqlalchemy.org/download.html

Mike rewrote most of it over time, but the concept is the same -- as part of the build/deploy process, the grid is automatically generated by querying PyPI for the raw data ( https://bitbucket.org/zzzeek/sqlalchemyorg/src/6d7045b6096c43a6b0f243cbd2b90bff01e5a5ed/_controllers/gen_releases.py?at=master&fileviewer=file-view-default )