Created unit tests for the OverallCFRecommender an DeltaCFRecommender classes
Modified the DummyPredictor class so it extends the BaseRecommender class
Modified MultiCriteriaBaseRecommender so it extends the BaseRecommender class, and also included a new module to build a user similarity matrix based on user ratings
Updated the unit tests for the SingleCF class so now it has a comparison against the DummyPredictor class
Created two new recommenders based on the single-criterion recommender system proposed by Adomavicius in 'New Recommendation Techniques for Multicriteria Rating Systems'
Created unit test for the two new recommender systems