Implement NLP transforms, KS alarm + detector

[Anmol-Srivastava]

As experimental code, this serves as an outline of the NLP framework rather than final versions. Closes #152

Added

• transforms (Representation removed) related to alibi-detect example
• basic Detector and KS test Alarm
• updated wilds_datasets.ipynb example to reflect testing on civil-comments dataset

Outstanding Issues

• design of the KS Alarm scheme -- test occurs feature-wise, but how should drift alarm?

[tms-bananaquit]

Will need to add citations and update references for alibi-detect's paper and/or documentation before merging the experimental branch.

[Anmol-Srivastava]

This is essentially ready to be merged in -- citations are added and the code is stable enough.

This also now closes #153 #154 and can enable proper integration into menelaus

[Anmol-Srivastava]

Now also closes #164

[tms-bananaquit]

• Should probably remove output (warnings) that references local files (e.g. c:\Users\ASRIVASTAVA)
• Should test building on readthedocs to make sure this renders correctly

[Anmol-Srivastava]

Resolving once I've done these