Tall hexagon for isolating delta tower errors

This is a tall hexagon that you can print on a deltabot to isolate errors in linear motion of your deltabot. Typical errors that you can spot from these are:

- idler/pulley runout (manifests as a repeated bump along Z of the affected side, period should be equal to circumference of your idler/pulley).
- linear motion wheel runout (manifests a consistent repeated wavy wall on the affected side, period should be equal to circumference of your wheel)
- slipping pulleys or missed steps (semi