Moved the fourcity_clusterer and similarity_matrix_buider modules to another package
Modified the extractor m
Removed legacy unused code
Renamed the fourcity_clusterer module to weights_similarity_matrix_builder
Added the dictionary_utils module that contains useful functions to work with dictionaries
Added nearest neighbor capability to single criterion recommender systems
Created the classes BaseSimilarityMatrixBuilder and SingleSimilarityMatrixBuilder that are in charge of building the similarity matrices, in this way, now recommenders can incorporate different types of similarities as components
Moved the build_user_clusters method to the MultiCriteriaBaseRecommender class
Transformed the weights_similarity_module into a class and integrated it with the MultiCriteriaBaseRecommender class