forked from dnprock's block: US States Map with Dropdown Selector
https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js
https://cdnjs.cloudflare.com/ajax/libs/topojson/1.1.0/topojson.min.js
https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js