v1.3.1

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: v1.3.0...v1.3.1