code: function(asyncFunc, callback) {
    asyncFunc(function(err, buffer) {
      if(callback) {
        callback(err, buffer.toHex().toString());
      }
    });
  }
docs: Helper for async functions that pass data through a callback in
  the form of (Error, Buffer). Will translate the Buffer to a hex
  String and pass that instead.
  @param {Function} asyncFunc Asynchronous function to call
  @param {Callback} callback