Merge branch 'feature/containerization' of https://github.com/Unity-Technologies/ml-agents into feature/containerization

docs/Using-Docker.md

 
 - Ensure that `unity-volume/<environment-name>.x86_64` and `unity-volume/environment-name_Data`. So for example, `<environment_name>` might be `3Dball` and you might want to ensure that `unity-volume/3Dball.x86_64` and `unity-volume/3Dball_Data` are both present in the directory `unity-volume`.
 
-
 - Make sure the docker engine is running on your machine, then build the docker container by running `docker build  -t <image_name> .` . in the top level of the source directory. Replace `<image_name>` by the name of the image that you want to use, e.g. `balance.ball.v0.1`.
 
 - Run the container:
 	 --docker-target-name=unity-volume \
 	 --train --run-id=<run-id>
 ```
-
 
 **Notes on argument values**