INT-1833: Add es6 to eslint env (#484)

Author: durran

.eslintrc

@@ -2,6 +2,7 @@
   "env": {
     "mocha": true,
     "node": true,
+    "es6": true
   },
   "rules": {
     "camelcase": 1

src/app/minicharts/d3fns/geo.js

@@ -424,6 +424,7 @@ var minicharts_d3fns_geo = function() {
         'stroke-width': 1
       });
 
+      /* eslint no-undef: 0 */
       render();
       _.defer(function() {
         map.resize();