Fixed timeout code to handle millis() rollover.  Not tested.
Ditto.
Tidied up variable initialisation and names.
Changed to "+= interval" pattern.
Removing debug print statements in animation
Changing LED strip length and working set of animations.
Changing number of LEDs.  Fixing gitignore.
Fixed return code.  Not tested.
Updating pin numbers and default animation for testing sensors.
Moved pushbutton hardware initialisation from constructor to begin method.
Fixed "wrong order of bins". Basic test OK with left sensor.
Set left animation to "all off".  Increased brightness of "off" state on both sides.