Minor bug fixes mostly relevant for macOSX, but fixed a critical bug related to the vessel model.
**Changes**:
- Included yaml-file as dependency, as it was not included before
- Updated path to yaml-file to work across operating systems
- Changed multiprocessing start method to "spawn" to work with macOSX
- Livermask now works without having CuPy installed and without needing to specify "--cpu" flag
**Full Changelog**: https://github.com/andreped/livermask/compare/v1.3.0...v1.3.1