title: Unhandled rejection TypeError: res.sendStatus is not a function
body: <p>I got this strange error in my application. As you can see in the <code>package.json</code> the <code>express</code> version is > <code>4.x</code>.</p>
  
  <pre><code>{
    "name": "MyAPI",
    "version": "1.0.0",
    "private": true,
    "scripts": {
      "start": "node ./bin/www"
    },
    "dependencies": {
      "bcrypt": "^0.8.6",
      "body-parser": "~1.13.2",
      "cookie-parser": "~1.3.5",
      "debug": "~2.2.0",
      "express": "~4.13.1",
      "jade": "~1.11.0",
      "morgan": "~1.6.1",
      "pg": "^4.5.5",
      "pg-hstore": "^2.3.2",
      "sequelize": "^3.23.2",
      "sequelize-cli": "^2.4.0",
      "serve-favicon": "~2.3.0",
      "validator": "^5.2.0"
    }
  }
  </code></pre>
  
  <p>Here is the source code</p>
  
  <pre><code>'use strict';
  var express = require('express');
  var router = express.Router();
  var version = require('../package.json').version;
  var sequelize = require('sequelize');
  
  var userAccounts = require('../models').user_account;
  
  router.post('/v' + version + '/register', function (res, req, next) {
      userAccounts.create(req.body).then(function () {
          next();
          return res.sendStatus(200).send({ message: ":D" });
      });
  });
  
  module.exports = router;
  </code></pre>
  
  <p>I also tried to change the <code>sendStatus</code> to <code>status</code> but the error says the same thing about <code>status</code> too. why I am getting these errors?</p>