navbar-toggler-icon not working
Demo: http://jsfiddle.net/u1s62Lj8/1/
You need the jQuery and Boostrap Javascript files included in your HTML page for the toggle to work. (Make sure you include jQuery before Bootstrap.)
<html>
<head>
// stylesheets here
<link rel="stylesheet" href=""/>
</head>
<body>
//your html code here
// js scripts here
// note jquery tag has to go before boostrap
<script src="https://code.jquery.com/jquery-2.1.3.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/js/bootstrap.min.js"></script>
</body>
</html>