Now that we're dropping 2.7 support, I've started to notice the points where supporting Python 3.3 requires extra work. For instance, 3.4 introduced pathlib and unittest.mock into the standard library, so we have a couple of dependencies which are only needed on 3.3.

It also means tests take longer, especially on Appveyor which only runs one build at a time.

Python 3.4 was released in March 2014, so it's not yet 2 years old. So I don't think we should drop 3.3 yet, but I wanted to open the discussion.