[WIP] guarddog

[eslerm]

Adds guarddog package. Most dependencies are required for tests. make passes, tests do not. Library test does not pass when uncommented/re-enabled. Not sure what best practices are for creating a Python package which provides a library and binary.

I can add the disposable_email_domains runtime depenency next. Help with import test and best practice advice is greatly appreciated.

I accidentally rebuilt py3-typing-extensions.yaml :sweat_smile: ig that will be a good check of my first packages.

cc: @egibs @antitree