Unfortunately, the demo/test code was written before we standardized all of our code to Arduino. The board does use an Arduino bootloader, so you can still use avrdude to load the hex file. If you look at the verbose output when you try and load code over arduino, you can copy the avrdude command and add the hex file from the repo to program the board.
EDIT: Here is a good avrdude tutorial. Use programmer flag stk500v2 to use the bootloader.