Merge remote-tracking branch 'upstream/develop' into develop-curriculum-learning-refactor

python/tests/mock_communicator.py

             camera_resolutions=resolutions,
             vector_action_descriptions=["", ""],
             vector_action_space_type=int(not self.is_discrete),
-            vector_observation_space_type=1,
             brain_name="RealFakeBrain",
             brain_type=2
         )

python/tests/test_unitytrainers.py

       "memorySize": 0,
       "cameraResolutions": [],
       "vectorActionDescriptions": ["",""],
-      "vectorActionSpaceType": 1,
-      "vectorObservationSpaceType": 1
+      "vectorActionSpaceType": 1
       }]
 }'''.encode()