GitHub Action for running Flake8 commands

Each time that new code is pushed into your repo, you can have a Flake8 command automatically run.

Find Python 3 syntax errors and undefined names with:

$ flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics

E901,E999,F821,F822,F823 are the "showstopper" flake8 issues that can halt the runtime with a SyntaxError, NameError, etc. These 5 are different from most other flake8 issues which are merely "style violations" -- useful for readability but they do not effect runtime safety.

• F821: undefined name name
• F822: undefined name name in __all__
• F823: local variable name referenced before assignment
• E901: SyntaxError or IndentationError
• E999: SyntaxError -- failed to compile a file into an Abstract Syntax Tree