attempt to get caching+ccache working on osx - refs https://blog.travis-ci.com/2016-05-03-caches-are-coming-to-everyone
attempt to get caching+ccache working on osx - refs https://blog.travis-ci.com/2016-05-03-caches-are-coming-to-everyone

naturalatlas/mapnik,tomhughes/mapnik,mapycz/mapnik,mapnik/mapnik,tomhughes/mapnik,pnorman/mapnik,mapnik/mapnik,zerebubuth/mapnik,naturalatlas/mapnik,mapnik/mapnik,naturalatlas/mapnik,pnorman/mapnik,lightmare/mapnik,pnorman/mapnik,zerebubuth/mapnik,naturalatlas/mapnik,mapnik/mapnik,lightmare/mapnik,mapycz/mapnik,zerebubuth/mapnik,tomhughes/mapnik,mapycz/mapnik,lightmare/mapnik,lightmare/mapnik,CartoDB/mapnik,pnorman/mapnik,CartoDB/mapnik,tomhughes/mapnik,CartoDB/mapnik