[Interpretable Model] Add support for Interpretable Decision sets

[pramitchoudhary]

This ticket is to extend the coverage for supporting natively interpretable models(Rule-based model). Interpretable Decision sets are similar to Bayesian Rule List(BRL) in-terms of the human understandable IF-ELSE conditional statements. However, unlike BRL the conditional rules are unordered and independent(flat IF-THEN statements). For more information check out the paper mentioned below, "H. Lakkaraju, S. H. Bach, and J. Leskovec. Interpretable decision sets: A joint framework for description and prediction. In Proceedings of the 22nd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, pages 1675–1684. ACM, 2016." Link

[thoth291]

It would be lovely to get this implemented. Any plans?