Tests now work as well

src/descriptor_identifier/Model/ModelClassifier.cpp

src/descriptor_identifier/Model/ModelRegressor.cpp

src/feature_creation/domain/Domain.cpp

tests/exec_test/check_model.py

tests/test_classification/test_classification.py

tests/test_descriptor_identifier/model_files/test.dat

tests/test_descriptor_identifier/model_files/train.dat

tests/test_descriptor_identifier/test_model.py

tests/test_descriptor_identifier/test_regressor.py

...feature_creation/test_feature_space/test_feature_space.py