Background
  ==========
  The BBC micro:bit board comes with its own little utility library, that makes
  some of the boards unique feature like the 5x5 LED matrix usable to RIOT.
  
  This test application is therefore specialized for only that board and its
  purpose is to test and showcase the board specific utility library.
  
  
  Expected result
  ===============
  When running this application, you should see the string
  `Welcome RIOT @ micro:bit!` scrolling by on the boards LED matrix.