Changelog
- Switch MDS implementation for [skbio](http://scikit-bio.org/docs/0.5.4/generated/generated/skbio.stats.ordination.pcoa.html) to [sklearn](https://scikit-learn.org/stable/modules/generated/sklearn.manifold.MDS.html)
- Add `all` to `-kne` to use all neighbors in training dataset for KNN source proportion estimation
- Code cleanup
- Github actions to build and upload new conda package from release
- Remove probability recalibration for KNN source estimation