Implement wasserstein fairness postprocessing

[nrkarthikeyan]

Implement algorithm 2 in http://proceedings.mlr.press/v115/jiang20a/jiang20a.pdf - a simple and efficient post-processing fairness method

[nrkarthikeyan]

A simplified example is here: https://gist.github.com/nrkarthikeyan/5727af2fc3d32aaec0ace1a1542bba17 This uses the original dataset instead of the barycenter as suggested in the algorithm but may be a good first cut.

[Nikitha-Narendra]

I would like to work on this issue