Drops Py3.7, improves typing and adds a mypy config, improves the docstrings and isorts the imports.
* configure isort
* sort with isort
* add github action
* enable flake8-docstrings
* fix docstrings
* add mypy env
* no implicit optional
* add type for raw
* add some type hints
* migrate
* abstract base class test
* remove assert_equal in test_cli
* remove nose from test_cli
* remove nose dependencies
* use tempfile
* configure coverage
* flag python version in name
* enable comment
* drop EOL py37
Patrick Kanzler