To run the code you need to change the references to p5.js files in the index.hmtl file. Those two lines can be replaced by the following 2 lines:
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/0.9.0/p5.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/0.9.0/addons/p5.dom.js"></script>