Enhance test coverage

Author: SabineHaas

tests/test_wind_turbine.py

@@ -38,4 +38,5 @@ def test_get_turbine_data_from_file(self):
                                        file_='not_existent')
 
     def test_get_turbine_types(self):
-        get_turbine_types(print_out=False)
+        get_turbine_types(print_out=True, filter_=True)
+        get_turbine_types(print_out=False, filter_=False)