Sldc

- support variable tile overlap in merger

- clean list of dependencies
- fix deprecation warnings
- add github actions

**Full Changelog**: https://github.com/waliens/sldc/compare/v1.4.0...v1.4.1

- optimization of merging algorithm (should handle better large numbers of polygons)
- fix some deprecation warnings (shapely, numpy)

**Full Changelog**: https://github.com/waliens/sldc/compare/v1.3.0...v1.4.0

- refactor CytomineTile to make different download types available (IIP, window)
- improve robustness: padding, cache directory creation
- CytomineSlide can be initialized with an ImageInstance directly

- drop support for python 2.7
- add smarter edge tiles management policies
- add support for batching at segmentation