Has anyone actually made a maze robot?

Has anyone actually had success with the GoPiGo, Ultrasonic Sensor, and Python to program the device to complete a maze by turning and moving toward the largest distance?

Not sure, however what your describing is possible.

We have not seen a maze solver yet, however it is doable. We had made an example a while back which used the servo and an ultrasonic sensor to map the region in front of the GoPiGo. If you expand on this, you should be able to create a maze solver.