Minetest Gymnasium interface v0

[garymm]

• [x] Synchronous Interface to MT that's hooked up to a MQ
• [x] Gym interface for MQ & MT process starting and resetting
• [x] Lua extensions for defining rewards
• [x] Headless
• [x] Figure out why performance is so bad on MacOS (non-headless) now
• [ ] Properly shutdown xvfb when the environment is being shut down
• [x] Add some assertions to alert user when minetest binary launched by the gym client has died, and where to find the logs
• [x] Properly deal with arguments passed to the gym client (socket number, world name, ...)
• [ ] Increasing number of Ticks per seconds
• [ ] Update irrlicht headless branch. I currently don't have acess

[garymm]

I tried running this inside a docker container on my mac and then connecting to it from the macOS host and I'm seeing crashes. I guess something is very wrong, so my current plan is:

• Make sure the current thing works and then merge it
• get a bazel build set up so I can be productive and use sanitizers
• go back and fix a bunch of stuff