Evaluation - pigs_tables

[JanBenisek]

• Add parameter model_type which can be [classification, regression]
• Based on the parameter, change names (we no longer talk about incidence rate)
• Document and write/modify unit tests

[sandervh14]

Committing what I have modified so far. I can spend time tomorrow on the unit test for regression and for trying out the results on the regression MVP test case.