title: Express-subdomain not seeing route
body: <p>I am using the example setup from the <a href="https://www.npmjs.com/package/express-subdomain" rel="nofollow noreferrer">https://www.npmjs.com/package/express-subdomain</a> package. However, when I try api.localhost:3000 in a browser it throws an error: "Cannot GET /"</p>
  
  <p>How can I get api.localhost:3000 running? I would consider other solutions, not just ones using <code>express-subdomain</code> as long as you don't have to type in the fqdn in the setup.</p>
  
  <p>app.js:</p>
  
  <pre><code>var subdomain = require('express-subdomain');
  var express = require('express');
  var app = express();
  
  // *** Code examples below go here! ***
  var router = express.Router();
  
  //api specific routes
  router.get('/', function(req, res) {
      res.send('Welcome to our API!');
  });
  
  router.get('/users', function(req, res) {
      res.json([
          { name: "Brian" }
      ]);
  });
  
  app.use(subdomain('api', router));
  app.listen(3000);
  </code></pre>
  
  <p>package.json:</p>
  
  <pre><code>{
    "name": "auth_manager",
    "version": "1.0.0",
    "description": "",
    "main": "app.js",
    "scripts": {
      "test": "echo \"Error: no test specified\" &amp;&amp; exit 1"
    },
    "author": "",
    "license": "ISC",
    "dependencies": {
      "express": "^4.16.3",
      "express-subdomain": "^1.0.5"
    }
  }
  </code></pre>