forked from wboykinm's block: multiple layers: gridLayer and tileLayer
Modified http://api.tiles.mapbox.com/mapbox.js/v1.6.2/mapbox.js to a secure url
Modified http://d3js.org/topojson.v1.min.js to a secure url
https://api.tiles.mapbox.com/mapbox.js/v1.6.2/mapbox.js
https://d3js.org/topojson.v1.min.js