appveyor: without vs2014 we can't source build, instead let's test binaries
appveyor: without vs2014 we can't source build, instead let's test binaries

tomhughes/node-mapnik,Uli1/node-mapnik,stefanklug/node-mapnik,CartoDB/node-mapnik,Uli1/node-mapnik,langateam/node-mapnik,langateam/node-mapnik,MaxSem/node-mapnik,langateam/node-mapnik,tomhughes/node-mapnik,CartoDB/node-mapnik,MaxSem/node-mapnik,tomhughes/node-mapnik,mapnik/node-mapnik,tomhughes/node-mapnik,stefanklug/node-mapnik,mapnik/node-mapnik,langateam/node-mapnik,CartoDB/node-mapnik,mapnik/node-mapnik,langateam/node-mapnik,MaxSem/node-mapnik,MaxSem/node-mapnik,Uli1/node-mapnik,Uli1/node-mapnik,tomhughes/node-mapnik,stefanklug/node-mapnik,mapnik/node-mapnik,mapnik/node-mapnik,CartoDB/node-mapnik,stefanklug/node-mapnik,CartoDB/node-mapnik