DisparateImpactRemover missing method implementations

[annapmeyer]

disparate_impact_remover.py only implements one method, fit_transform. But the documentation indicates that fit, fit_predict, predict, and transform should also be methods for this class. The class inherits these methods from the Transformer class, however, they are not implemented in that class, either.

Either the documentation should be updated, or the methods should be implemented. I suspect the latter, because fit_transform would only be appropriate to run on training data. For test/validation data, there should be a transform function available.