Pin the Google Maps API version to v3.47. (#1681)

See this piece of documentation: https://developers.google.com/maps/documentation/javascript/browsersupport.
Version 3.47 of the Maps Javascript API will be the last version to support IE11.

TEST=manual

Saw v3.47 of the API being used. Saw Google Maps appear on Universal as expected.

src/ui/components/map/providers/googlemapprovider.js

@@ -98,7 +98,7 @@ export default class GoogleMapProvider extends MapProvider {
         onLoad();
       },
       async: true,
-      src: `https://maps.googleapis.com/maps/api/js?${self.generateCredentials()}&language=${self._language}`
+      src: `https://maps.googleapis.com/maps/api/js?${self.generateCredentials()}&language=${self._language}&v=3.47`
     });
 
     DOM.append('body', script);