Expose velocity attribute

Author: tekktrik

adafruit_midi/note_off.py

@@ -38,17 +38,17 @@ class NoteOff(MIDIMessage):  # pylint: disable=duplicate-code
     def __init__(self, note, velocity=0, *, channel=None):
         self.note = note_parser(note)
         """key, either int (0-127) or string that will be turned off """
-        self._velocity = velocity
+        self.velocity = velocity
         super().__init__(channel=channel)
-        if not 0 <= self.note <= 127 or not 0 <= self._velocity <= 127:
+        if not 0 <= self.note <= 127 or not 0 <= self.velocity <= 127:
             self._raise_valueerror_oor()
 
     def __bytes__(self):
         return bytes(
             [
                 self._STATUS | (self.channel & self.CHANNELMASK),
                 self.note,
-                self._velocity,
+                self.velocity,
             ]
         )