message: updated example to Promise api
  [skip ci]
diff: @@ -17,7 +17,7 @@ define(["Tone/core/Tone", "Tone/component/Volume"], function(Tone){
  * var motu = new Tone.UserMedia();
  *
  * //opening the input asks the user to activate their mic
  - * motu.open(function(){
  + * motu.open().then(function(){
  * //opening is activates the microphone
  * //starting lets audio through
  * motu.start(10);
  