text: module.exports = app => {
      //error report view
      app.use(function (req, res) {
          res.status(404);
          // respond with html page
          if (req.accepts('html')) {
              res.render('error');
              return;
          }
          // respond with json
          if (req.accepts('json')) {
              res.send({ error: 'Not found' });
              return;
          }
          // default to plain-text. send()
          res.type('txt').send('Not found');
      });
  }