message: meter measures and returns RMS
diff: -define(["Tone/core/Tone", "helper/Meter"], function (Tone, Meter) {
  +define(["helper/Offline"], function (Offline) {
  return function(callback, duration, channels){
  - var meter = new Meter(duration, channels);
  -
  - meter.before(function(output){
  - callback(output, function testFn(cb){
  - meter.test(cb);
  - }, function(cb){
  - meter.after(cb);
  - });
  + return Offline(callback, duration, channels).then(function(buffer){
  + var blockTime = 512/buffer.sampleRate;
  + var rms = buffer.getRMS(512);
  + rms.forEach = function(callback){
  + for (var i = 0; i < rms.length; i++){
  + var level = rms[i];
  + callback(level, blockTime * i);
  + }
  + };
  + return rms;
  });
  -
  - meter.run();
  };
  });
  \ No newline at end of file
  