adding test data directory to gitignore
adding test data directory to gitignore

1ec5/carto,clhenrick/carto,CartoDB/carto,pnorman/carto,tomhughes/carto,midnightcomm/carto,gravitystorm/carto,CartoDB/carto,mapbox/carto,stefanklug/carto,whitelynx/carto,madeinqc/carto