Stockwell

- Use ctypes to wrap the modules written in C
- License changed to GPLv3

- Packages for Python 3.10 and macOS arm (M1, M2)

- Fix for missing file in source distribution

- New parameters for `st.st()`: `gamma` and `win_type`:
- `gamma` can be used to tune the time and frequency resolutions
of the S-transform.
- `win_type` can be set to 'gauss' (default) and 'kazemi' (Kazemi, 2014)

- Use `versioneer` to generate package version
- Add tests

- Automated wheel building and deploy to PyPI