upgrade to python 3

[charlesreid1]

this lib does not work in python 3

[JD-P]

I was actually just about to do a python3 compatibility series of edits, but figured I'd check in first to see if the author (@chaselgrove) will accept them.

[chaselgrove]

Thank you both. (And sorry for the delay; I was on vacation.)

@JD-P: what was your issue with the Python 2 tests?

[chaselgrove]

0.2.0 in PyPI.