Python 2-only but not documented as such

[rpavlik]

Tried installing it with pip3 which "worked" but gave an HTMLParser error. Presumably, it could be worked around similarly to this: https://github.com/DTVD/rainbowstream/blob/master/rainbowstream/py3patch.py#L16

(Additionally, even with python 2, on debian stretch, it appeared to hang or at least take an exceedingly long time comparing two 1.4MB files... strangely it doesn't appear to be using much in the way of CPU.)

[danyill]

@rpavlik I've had a little bash at making some minor improvements from the issue list and porting this to Python 3 in my fork. My Python skills are modest but it appears to work...

[NDagestad]

This seems to have been fixed in 590c554. can we close this issue please? Random people coming to the repo might be confused otherwise (I am the random user 🙃)