use mapnik-config as proxy for whether to run mason installs
use mapnik-config as proxy for whether to run mason installs

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