The Guyou projection is available as d3.geo.guyou
in the geo.projection D3 plugin.
Modified http://d3js.org/d3.v3.min.js to a secure url
Updated missing url https://raw.github.com/d3/d3-plugins/master/geo/projection/projection.js to https://cdn.jsdelivr.net/gh/d3/d3-plugins/geo/projection/projection.js
Changed ajax call from /d/3682676/readme-boundaries.json to /mbostock/3682676/example/readme-boundaries.json.
Changed ajax call from /d/3682676/readme-land.json to /mbostock/3682676/example/readme-land.json.
https://d3js.org/d3.v3.min.js
https://raw.github.com/d3/d3-plugins/master/geo/projection/projection.js