Add TORCS environment

[YurongYou]

Hi, I have wrapped the TORCS (The Open Racing Car Simulator) environment into an interface with rlenv API! See https://github.com/YurongYou/rlTORCS. Maybe we can add this racing car simulator environment into rlenvs?

[Kaixhin]

This looks awesome! Please go ahead and submit a PR. You will need to:

• Add it to the README
• Provide a short set of installation requirements (see Minecraft for an example) - you can point to your repo for further details
• Provide one environment file
• Add the environment file to the rockspec and rlenvs/init