How to download ARTv1 maya ToolKit when using UE4 source engine?

Found the solution.

As of writing of this post, ARTv2 is fairly stable and feature complete, and you can clone it here:

https://github.com/EpicGames/ARTv2

To install:
Open Maya, drag install.mel into maya 3d viewport.

If you have script error, try changing:

python("if not os.path.exists(mayaModDir): os.path.makedirs(mayaModDir)");

to

python("if not os.path.exists(mayaModDir): os.path.os.makedirs(mayaModDir)");