Doing the first PyPi release from GitHub

Make this into a real package and prepare for publish on PyPi (#1)

* preparation stuff for publishing on pypi

* follow some example on https://python-packaging.readthedocs.io/en/latest/command-line-scripts.html

* setup with a command line installer

* update the readme and cleanup code to work in module form

* simplify without named args

* handle weekends and weekdays and nicer readme

* Update README.md

* Remove codecov

* cleanup for flake