Implement DELIP

Implement Data-Efficient model-Learning In POMDPs (DELIP) [1].

[1] Tschiatschek, S., Arulkumaran, K., Stühmer, J., & Hofmann, K. (2018). Variational Inference for Data-Efficient Model Learning in POMDPs. [*arXiv preprint arXiv:1805.09281*](https://arxiv.org/abs/1805.09281).