* Update requirements
* Update incompatible scipy version
* Reduce runtime of dataset assessment tests
* ncp is now a class that contains 3 values: fit_score, transform_score and generalizations_score so that it doesn't matter in what order the different methods are called, all calculated ncp scores are stored.
Generalizations can now be applied either from tree cells or from global generalizations struct depending on the value of generalize_using_transform. Representative values can also be computed from global generalizations.
Removing a feature from the generalization can also be applied in either mode.
* Compute generalizations with test data when possible (for computing better representatives).
* Externalize common test code to methods.
