title: Place a marker in each country with mapbox
body: <p>I am using Mapbox to build a multiple choropleth map.
  Something along the lines of this example, <a href="https://www.mapbox.com/mapbox.js/example/v1.0.0/choropleth-joined-data-multiple-variables/" rel="nofollow">https://www.mapbox.com/mapbox.js/example/v1.0.0/choropleth-joined-data-multiple-variables/</a></p>
  
  <p>I am using countries instead of US states however.
  I've got the map working and I can switch between layers
  I have an extra requirement however to add a marker in each country that displays how many projects are active in that country.
  I found out how I can add custom markers to the map with this example, <a href="https://www.mapbox.com/mapbox.js/example/v1.0.0/divicon/" rel="nofollow">https://www.mapbox.com/mapbox.js/example/v1.0.0/divicon/</a></p>
  
  <p>The problem is I need to put a marker in the center of each country.
  Does anybody know a way to put a marker in the middle of each country?</p>
  
  <p>I tried to use the natural earth admin 0 label points data but that has multiple points per country. It looked like the 'scalerank=0' points were the middle of the countries but if I filter on these points, I still get multiple points for some countries (russia has 4 for instance, but Belgium has 4 as well).
  If you plot all scalerank 0 points on a map you get the following result:
  <a href="https://a.tiles.mapbox.com/v4/persyval.jg5p7gm7/page.html?access_token=pk.eyJ1IjoicGVyc3l2YWwiLCJhIjoiX3lrSTNYYyJ9.6Ps4OlBCYmlkxQksKsGb7A#6/45.159/12.206" rel="nofollow">https://a.tiles.mapbox.com/v4/persyval.jg5p7gm7/page.html?access_token=pk.eyJ1IjoicGVyc3l2YWwiLCJhIjoiX3lrSTNYYyJ9.6Ps4OlBCYmlkxQksKsGb7A#6/45.159/12.206</a></p>
  
  <p>Does anybody know about a dataset that has one point per country or another way to put a marker in the center of each country with mapbox?</p>