Bootstrap Toggle still displaying as a checkbox

I am trying to implement a toggle switch using http://ift.tt/1q1Vzos

I have added the following into my page:

<link href="http://ift.tt/2aDsFEU" rel="stylesheet">
<script src="http://ift.tt/2aDrLs2"></script>

and simply implemented the toggle switch using:

<input type="checkbox" checked data-toggle="toggle">

However, it still displays as a checkbox and not the toggle switch, any ideas? Thanks :)