Blendmodes

- use aenum

- Mark deprecated functions with deprecated decorator
- add blendtype.py and change BlendType to str enum

- Deprecated 'raster' functions and replaced with more accurate naming
- Typing improvements
- Update deps

2021 - 2021/04/16

- Updated typing (removed data-science-types)
- Updated formatting
- Improved docstrings
- Update tests

- Using FHMake to build
- Added type hinting
- Dropped support for python < 3.7
- Added support for python 3.9

- Removed `scikit-image`
- Now compatible with python 3.5

- Updated classifiers