Shut off workers with buggy docker daemon

[truell20]

We've had problems with docker failing. To mitigate this, we should check to see that docker is working properly before running each game.

[Janzert]

Pre-testing still leaves the possibility of the game run failing. It might be better to inspect the error result from the actual game. Of course this would also have to be done carefully to ensure a rogue bot couldn't fake it.

[truell20]

I liked to the wrong forum post. Meant to point to this issue: http://forums.halite.io/t/bot-error-due-to-docker/570/11.

Have updated the initial description of the issue as well.