Alpine-based version of Python Black for reproducible usage in CI

Tiny Alpine-based multistage-build dockerized version of Black^[1].

^{[1] Official project: https://github.com/python/black}

The working directory inside the Docker container is /data/ and should be mounted locally to the root of your project.

# Linux, Mac, Windows (Powershell)
docker run --rm -v $(pwd):/data prybalko/black main.py

# Windows (cmd)
docker run --rm -v �%:/data prybalko/black main.py

MIT License

Copyright (c) 2019 prybalko