Merge pull request #889 from Unity-Technologies/hotfix-setup-version

Update setup version to v0.4

python/setup.py

     required = f.read().splitlines()
 
 setup(name='unityagents',
-      version='0.3.0',
+      version='0.4.0',
       description='Unity Machine Learning Agents',
       license='Apache License 2.0',
       author='Unity Technologies',