code: function deleteAppConfig(connections, options, appConfig, cb) {
      logger.debug('deleteAppConfig()');
      validateParams(connections, options, appConfig, ["appId"], function(err) {
        if (err) {
          return cb(err);
        }
        var conn = connections.mongooseConnection;
        var appConfigModel = models.get(conn, models.MODELNAMES.APP_CONFIG);
        logger.debug('deleteAppConfig() - validated about to search for: ', appConfig.appId);
        appConfigModel.findOne({appId:appConfig.appId}).exec(function(err, config) {
          if (err) {
            return cb(err);
          }
          if (!config) {
            logger.warn('deleteAppConfig() - appConfig not found for: ', appConfig.appId);
            return cb(new Error('appConfig not found'));
          } else {
            logger.debug('deleteAppConfig() - deleting: ', appConfig.appId);
            config.remove(cb);
          }
        });
      });
    }
docs: /*
  deleteAppConfig(connections, options, appConfig, cb)
  
  connections: {
  mongooseConnection: ...
  }
  
  options: {
  uri:       db connection string,
  userEmail: user email address string
  }
  
  appConfig: {
  appId: id of the app
  }
  
  cb  - callback function (err)