pypi2port and python supported versions

[db]

I used pypi2port to get the basic porfile for stem module, emended and submitted it in #54014. I was told to remove py34 and add py36. pypi2port usually writes 27 34 35 in python.versions, although 33 is still supported (now for a couple of months) and 36 is already released.

What is the general consensus for python versions? Should pypi2port be updated for 27 35 36? I know the latter's a minor thing, but it could be addressed nonetheless.