Merge pull request #25 from prcutler/root-group-fix

Update to use root_group for CP 9 compatibility

Author: dhalbert

examples/miniqr_displaytest.py

@@ -45,7 +45,7 @@ def bitmap_QR(matrix):
 
 splash = displayio.Group(scale=scale)
 splash.append(qr_img)
-board.DISPLAY.show(splash)
+board.DISPLAY.root_group = splash
 
 # Hang out forever
 while True: