[Announcement] AIcrowd repo2docker base image update

Hi everyone,

This is to inform that new release for aicrowd-repo2docker is pushed to pypi and GitHub with version .
The new release will use nvidia/cuda:10.0-cudnn7-runtime-ubuntu18.04 as the base image going forward.

I noticed that many participants especially in the Unity Obstacle Tower Challenge have been facing issues getting their code built with the new version of aicrowd-repo2docker as it ships with py37 by default, which is not supported by mlagents-env.

A quick trick to get around that is by including a file called as runtime.txt at the root of your repository, and as it contents have python-3.6.

Reference : https://repo2docker.readthedocs.io/en/latest/config_files.html#runtime-txt-specifying-runtimes