[FIX] TensorCoFi through file
[CHANGE] Interface from interface model to model package with name IModel.
[CHANGE] PEP-8 methods name in interface
[CHANGE] Arrange TensorCoFi attributes name
[CHANGE] Model interface now has the fit map the pandas DataFrame user Series and item Series. Than calls the train method. The train method should be the one to implement assuming the input is a numpy array with column one to users, column two to item and column three to rating