Vision works on red balls and is fast enough for the checkoff (about 10
times per second). After detecting contours it classifies sufficiently
large contours as balls and computes their bounding circles. Bounding
circles are ideal for vision because they look the same from all angles.

TODO:
-reformat to put everything in methods
-video feed from camera
-green balls
-more complicated stuff (green button vs ball, locate tower, etc)