Move Navigation bar to right in bootstrap

I've been trying to move the navigation bar in bootstrap4 to the right side of the screen by using float: right; on the nav a and it just is not doing anything. I'm using a codepen app to write my code for a project I'm doing.

<div class="container-fluid">
<class="row">
<header>
<nav class="navbar navbar-fixed-top">
<a href="#" class="glyphicon glyphicon-user">About</a>
<a href="#" class="glyphicon glyphicon-th-large">Portfolio</a>
<a href="#" class="glyphicon glyphicon-envelope">Contact</a>
</div>
</nav>
</header>
</div>
</div>
</body>
</html>

    @import url('//netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap-glyphicons.css');

nav a {
  color: black;
  padding: 10px;
  font-size: 32px;
  background-color: gray;
}