title: Mongoose not interacting with DB
body: <p>Code never executes to the <code>console.log("in")</code> so <code>findOne</code> is not being run. RoboT3 also doesnt show <code>auth</code> db. Mongo version is the latest 4.0.3.</p>
  
  <p><strong>controllers/authentication.js</strong></p>
  
  <pre><code>const User = require('../models/user');
  
  exports.signup = (req, res, next) =&gt; {
      console.log(req.body)
      const email = req.body.email;
      const password = req.body.password;
      // check for duplicate users by email
      User.findOne({email: email}, (err, existingUser) =&gt; { 
          console.log("in")
          if (err) {return next(err)}
  
          // if duplicate found, return error
          if (existingUser) {
              return res.status(422).send({error: 'Email is in use'});
          }
  
          const user = new User({
              email: email,
              password: password
          });
  
          user.save((err) =&gt; {
              if (err) {return next(err); }
              res.json(user);
          })
  
      });
      // if not, create and save record and return
  }
  </code></pre>
  
  <p><strong>index.js</strong></p>
  
  <pre><code>const express = require('express');
  const http = require('http');
  const bodyParser = require('body-parser');
  const morgan = require ('morgan');
  const router = require('./router');
  const mongo = require('mongodb');
  
  
  mongo.connect('mongodb://localhost:27017/auth', { useNewUrlParser: true });
  
  const App = express();
  // App setup
  App.use(morgan('combined'));
  App.use(bodyParser.json());
  router(App);
  
  // Server setup
  const port = process.env.PORT || 3090;
  const server = http.createServer(App);
  
  server.listen(port);
  
  console.log("server running on port " + port);
  </code></pre>
  
  <p><strong>router.js</strong></p>
  
  <pre><code>const authentication = require('./controllers/authentication');
  
  module.exports = function (app) {
      app.post('/signup', authentication.signup);
  }
  </code></pre>
  
  <p><strong>models/user.js</strong></p>
  
  <pre><code>const mongoose = require('mongoose');
  const Schema = mongoose.Schema;
  
  const userSchema = new Schema ({
      email: {type: String, unique: true, lowercase: true},
      password: String
  });
  
  const ModelClass = mongoose.model('user', userSchema);
  
  module.exports = ModelClass;
  </code></pre>