rm textfont.family settting (for now),

- it can lead to error in the case where mapbox doesn't
  have to requested font.

Author: etpinard

src/traces/scattermapbox/convert.js

@@ -111,10 +111,12 @@ module.exports = function convert(calcTrace) {
             var textOpts = calcTextOpts(trace);
 
             Lib.extendFlat(symbol.layout, {
-                'text-font': trace.textfont.textfont,
                 'text-size': trace.textfont.size,
                 'text-anchor': textOpts.anchor,
                 'text-offset': textOpts.offset
+
+                // TODO font family
+                //'text-font': symbol.textfont.family.split(', '),
             });
 
             Lib.extendFlat(symbol.paint, {