Fix neopixel buffer implementation

Writing to the neopixels currently uses an integer array. Implement functionality to use an unsigned int to pass in data.

some context from April 26, 2020 " I'll agree with Bob here on using an unsigned char (I prefer uint8). Using the integer array unnecessarily uses much more memory and makes the representation of a 'byte' confusing. Since we are always writing three bytes I would rather like a function that intakes an array of 3 uint8 to be written at once... this would simplify things. If you want to be able to take less than 3, you can add a length parameter.

If you want, you can merge this PR as-is and fix this and create a separate issue + PR."

uwrobotics / MarsRoverFirmware

Fix neopixel buffer implementation #75