Add robotMaze move limitation for the robot

[Asuza]

Because of the possibility to beat the level simply by luck (simply letting the robot move around randomly by holding down the R key), it would be a good challenge to add a robot limitation of fuel or charge, so that it can only go a certain number of steps before it can't move any further.

The limitation could definitely be high (enough for back-tracking and moving around the maze) but not so high that you can allow the robot to move around indefinitely. I would think 400 moves would be reasonable, but I haven't seen others' solutions yet, either.