Updated missing url https://cdn.rawgit.com/fabid/d3-heatmap/master/heatmap.js to https://cdn.jsdelivr.net/gh/fabid/d3-heatmap/heatmap.js
https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js
https://cdn.rawgit.com/fabid/d3-heatmap/master/heatmap.js