cuda version / docker

[MishaLaskin]

Thanks for open-sourcing the code Alex! What version of cuda / cudnn is your machine using? I'm trying to reproduce your results but it's failing to run on my two machines - one is cuda 10.1 / cudnn 7.6 and the other cuda 10.2 / cudnn 7.5.

It could be useful to also release a docker file so that we can build an image and run from there