GitHub Action to lint Python code

[cclauss]

Results at https://github.com/cclauss/Friends_Hack/actions

Python 3 treats Indentation Errors as Syntax Errors so https://pypi.org/project/reindent should be run on these five files.

1     E902 IndentationError: unindent does not match any outer indentation level
4     E999 IndentationError: expected an indented block
15    F821 undefined name 'Actor'
20