Subject: Python dependency compatibility badges

We have a pull request to add Pypi dependency compatibility badges to
our readme: This looks
generally useful, though highlights how out of date we still are in
some areas. Any thoughts on this? Given the high visibility, I wanted
to get some consensus (even if just lazy) before merging.

For reference, the badges (and their target links) are

[![Compat Check PyPI]

[![Compat Check Github]