2.1.0 for 3dball

ml-agents/setup.py

         "protobuf>=3.6",
         "pyyaml",
         "six>=1.12.0",
-        "tensorflow==2.2rc3",
+        "tensorflow==2.1.0",
         'pypiwin32==223;platform_system=="Windows"',
     ],
     python_requires=">=3.6.1",