This block shows how to use the geoMercatorEquatorialGuinea projection from d3-composite-projections.
Modified http://d3js.org/topojson.v1.min.js to a secure url
https://d3js.org/d3.v4.min.js
https://d3js.org/topojson.v1.min.js
https://unpkg.com/d3-composite-projections@1.2.0/d3-composite-projections.min.js