Fix argument mutation and incorrect result when attempting to reuse P…

…athOverlay coordinates in getStaticImage config (#413)

Array.prototype.reverse() reverses an array in place. This results in the (unintended) mutation of the coordinates property of the overlay param. Instead, create a new array and initialize it with the reversed lat and long.

 https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reverse

services/static.js

@@ -431,7 +431,7 @@ function encodePathOverlay(o) {
   }
   // polyline expects each coordinate to be in reversed order: [lat, lng]
   var reversedCoordinates = o.coordinates.map(function(c) {
-    return c.reverse();
+    return [c[1], c[0]];
   });
   var encodedPolyline = polyline.encode(reversedCoordinates);
   result += '(' + encodeURIComponent(encodedPolyline) + ')';