Added missing lookup table, fixed pep8 formatting

Added lookup_table.npy which was missing from the previous commit. The
led.py module uses this table to do LED brightness gamma correction.
Fixed formatting for pep8 compliance

python/led.py

@@ -70,6 +70,7 @@ def rainbow(brightness=255.0, speed=1.0, fps=10):
         update_pixels()
         time.sleep(1.0 / fps)
 
+
 if __name__ == '__main__':
     for i in range(N_pixels):
         set_all(0, 0, 0)