index.html

<!doctype html>
<html>
  <head>
    <title>CityBook</title>
    <link rel="icon" type="image/png" href="./img/favicon-32x32.png" sizes="32x32" />
    <link rel="icon" type="image/png" href="./img/favicon-16x16.png" sizes="16x16" />
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="manifest" href="/manifest.json">

    <!-- Bootstrap CSS -->
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/latest/css/bootstrap.min.css">
    <link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3/css/font-awesome.min.css" rel="stylesheet" integrity="sha384-T8Gy5hrqNKT+hzMclPo118YTQO6cYprQmhrYwIiQ/3axmI1hQomh7Ud2hPOy8SP1" crossorigin="anonymous">
  </head>
  <body>
    <div id='root'>
    </div>
    <script src="/static/bundle.js"></script>
  </body>
  <script type="text/javascript">
    if ('serviceWorker' in navigator) {
      window.addEventListener('load', function() {
        navigator.serviceWorker.register('/sw.js').then(function(registration) {
          console.log('ServiceWorker registration successful with scope: ', registration.scope);
        }).catch(function(err) {
          console.log('ServiceWorker registration failed: ', err);
        });
      });
    }
  </script>
</html>