add v0.9.6 to changelog
add v0.9.6 to changelog

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