text: const router = require('express').Router();
  let User = require('../models/users.model');
  
  router.route('/').get((req, res) => {
      User.find()
      .then(users => res.json(users))
      .catch (err => res.status(400).json('Error: ' + err));
  });
  
  router.route('/add').post((req, res) => {
      const username = req.
  })