Removes calibration code

Calibration will be done via the serial, since there is now only one
button and one led it is much harder to calibrate the device with out
more input. So the device will be calibrated over serial then a top
board can calibrate the base over serial as it will have much greater
input.
Adds an openscad model for the chassis

This allows you to print the chassis on any 3d printer. It is not
currently designed to be manufactuable by other means other than 3d
printing.