revisit stamen attribution

Author: archmoj

src/plots/mapbox/constants.js

@@ -4,7 +4,7 @@ var requiredVersion = '1.10.1';
 
 var OSM = '<a href="https://www.openstreetmap.org/copyright" target="_blank">© OpenStreetMap</a> contributors';
 var carto = '<a href="https://carto.com/" target="_blank">© CARTO</a>';
-var stamen = 'Map tiles by <a href="https://stamen.com">Stamen Design</a>, under <a href="https://creativecommons.org/licenses/by/3.0">CC BY 3.0</a>';
+var stamen = '<a href="https://stamen.com" target="_blank">© Stamen Design LLC</a>';
 
 var stylesNonMapbox = {
     'open-street-map': {