message: Allow port to be specified in public address
  Download files using binary encoding
diff: @@ -43,7 +43,7 @@ function Sparkbot(configuration) {
  } else if (endpoint.protocol != 'https:') {
  throw new Error('Please specify an SSL-enabled url for your public address: ' + controller.config.public_address);
  } else {
  - controller.config.public_address = endpoint.hostname;
  + controller.config.public_address = endpoint.hostname + (endpoint.port ? ":" + endpoint.port : '');
  }
  }
  @@ -461,6 +461,7 @@ function Sparkbot(configuration) {
  headers: {
  'Authorization': 'Bearer ' + controller.config.ciscospark_access_token
  },
  + encoding: 'binary',
  }, function(err, response, body) {
  cb(err, body);
  