Added script to init submodules
Added script to init submodules

CartoDB/node-mapnik,tomhughes/node-mapnik,CartoDB/node-mapnik,tomhughes/node-mapnik,mapnik/node-mapnik,mapnik/node-mapnik,tomhughes/node-mapnik,CartoDB/node-mapnik,CartoDB/node-mapnik,tomhughes/node-mapnik,mapnik/node-mapnik,tomhughes/node-mapnik,CartoDB/node-mapnik,mapnik/node-mapnik,mapnik/node-mapnik