message: Add delete_target_audience
diff: @@ -499,6 +499,9 @@ function Facebookbot(configuration) {
  };
  facebook_botkit.api.messenger_profile.postAPI(message);
  },
  + delete_target_audience: function() {
  + facebook_botkit.api.messenger_profile.deleteAPI('target_audience');
  + },
  postAPI: function(message) {
  request.post('https://graph.facebook.com/v2.6/me/messenger_profile?access_token=' + configuration.access_token,
  {form: message},
  