Remove python 2 support and assume we have python 3.3+

[behrmann]

I had this lying around on some private branch, seeing the movement here, I remembered that I might push it. Python 2 has been EOL for 2 years now and everything older 3.7 is EOL as well, so assuming Python 3.3+ seems sensible (also nothing older thatn 3.7 is being tested).

[keszybz]

Yeah, but let's do this for the next release.

[behrmann]

Sure, no worries. This is not really pressing. I still had this lying around from when I was last looking at the code and wanted to make it a bit easier to read for myself.

What I wondered: Is there a deeper reason behind this being extension modules instead of e.g. ctypes?

[thatguystone]

Is there any reason to restrict to 3.3+? I have type-hints locally that would be nice to get merged, but that requires 3.5+.

[thatguystone]

Is there any reason to restrict to 3.3+? I have type-hints locally that would be nice to get merged, but that requires 3.5+.

[behrmann]

Well, it does make the code easier to follow and everything pre-3.7 is EOL upstream. The system's running EOL Python versions probably don't need the newest version of this module and will be served by an older version.