Added fix for prototype.js > 1.7.3

humps.js

@@ -79,7 +79,7 @@
     return obj === Object(obj);
   };
   var _isArray = function(obj) {
-    return toString.call(obj) == '[object Array]';
+    return  'isArray' in Array ? Array.isArray(obj) : toString.call(obj) == '[object Array]';
   };
   var _isDate = function(obj) {
     return toString.call(obj) == '[object Date]';