unittest is much more straightforward without any magic. In a small
project like podman-compose being easy to understand is more important
than features.
Signed-off-by: Povilas Kanapickas <povilas@radix.lt>
Black removes the burden of manual code formatting and is by now
considered the standard Python formatting tool.
https://black.readthedocs.io/en/stable/
Format all Python code with black.
GitHub linting action is updated to ensure all files are formatted with
Black.
Signed-off-by: Piotr Husiatyński <phusiatynski@gmail.com>