This is the only class that includes property setters for two of the
attributes, which are untested, and even if they were used, would have
no impact since there is no method to submit the changes back to GitHub.
Drop them.
With the Python 2.7 deadline fast approaching, modernize the codebase
making use of the modernize module to switch to using six, as well as
other upcoming features, such as absolute imports . Stop using 2to3
for Travis, yay!
Steve Kowalik