Add extra colours, check for tuples and convert to ints when setting pixels
Add extra colours, check for tuples and convert to ints when setting pixels

  - Added constants for CYAN, MAGENTA and YELLOW

  - Added check in set_pixel() to see if the colour is given as a tuple,
     if so then the tuple is converted automatically into an int

fraz3alpha/led-disco-dancefloor,fraz3alpha/DDRPi