Turns out this is not the gi.repository but a different package:
'Command line to private gist. Example: gi.py myFile'
It's incompatible with python3 and fails on import and seems to conflict with
gi.repository (also, the upstream seems dead).
Fixes#103
Instead of failing with a syntax error on format strings, actually bail out
instead. Likewise for setup.py, require 3.6 and add this to the classifiers
too while we're there.
Related to #71