use latest mapnik-ref
use latest mapnik-ref

mapbox/mapbox-studio,Zhao-Qi/mapbox-studio-classic,mapbox/mapbox-studio,mapbox/mapbox-studio,mapbox/mapbox-studio-classic,Zhao-Qi/mapbox-studio-classic,mapbox/mapbox-studio-classic,mapbox/mapbox-studio,Zhao-Qi/mapbox-studio-classic,mapbox/mapbox-studio-classic,mapbox/mapbox-studio,Zhao-Qi/mapbox-studio-classic,mapbox/mapbox-studio-classic,Zhao-Qi/mapbox-studio-classic