adds alpha marker for heatmaps
adds alpha marker for heatmaps

splashblot/dronedb,codeandtheory/cartodb,DigitalCoder/cartodb,raquel-ucl/cartodb,future-analytics/cartodb,CartoDB/cartodb,raquel-ucl/cartodb,UCL-ShippingGroup/cartodb-1,CartoDB/cartodb,raquel-ucl/cartodb,future-analytics/cartodb,splashblot/dronedb,DigitalCoder/cartodb,UCL-ShippingGroup/cartodb-1,CartoDB/cartodb,nyimbi/cartodb,dbirchak/cartodb,DigitalCoder/cartodb,nyimbi/cartodb,splashblot/dronedb,DigitalCoder/cartodb,thorncp/cartodb,nuxcode/cartodb,nyimbi/cartodb,codeandtheory/cartodb,future-analytics/cartodb,splashblot/dronedb,bloomberg/cartodb,CartoDB/cartodb,dbirchak/cartodb,future-analytics/cartodb,bloomberg/cartodb,codeandtheory/cartodb,thorncp/cartodb,raquel-ucl/cartodb,UCL-ShippingGroup/cartodb-1,UCL-ShippingGroup/cartodb-1,dbirchak/cartodb,nuxcode/cartodb,bloomberg/cartodb,CartoDB/cartodb,nyimbi/cartodb,DigitalCoder/cartodb,bloomberg/cartodb,bloomberg/cartodb,nyimbi/cartodb,nuxcode/cartodb,splashblot/dronedb,nuxcode/cartodb,nuxcode/cartodb,thorncp/cartodb,dbirchak/cartodb,UCL-ShippingGroup/cartodb-1,future-analytics/cartodb,dbirchak/cartodb,raquel-ucl/cartodb,codeandtheory/cartodb,thorncp/cartodb,codeandtheory/cartodb,thorncp/cartodb