Github Actions

[Santobert]

After #63 we can now enforce that our code is formatted according to Black's guidelines. We could also use Pylint to apply some linting. This PR introduces Github Actions to automate these processes. The improves the review process.

• Add Github Actions for black and pylint
• Add pylintrc (settings file)
• Sort imports to make pylint happy
• Add comments to exclude a few lines from linting
• Fix some minor flaws

The result can be seen here: https://github.com/Santobert/pybotvac/runs/1413197056

If that's wanted we can build upon this in the future. Possible enhancements are:

• Security checks with bandit
• Automated releases
• Automated tests
• ...