update babel dev dependency and use for-of in sliced-to-array helper - fixes #1047

src/babel/transformation/templates/sliced-to-array.js

@@ -3,7 +3,7 @@
     return arr;
   } else if (Symbol.iterator in Object(arr)) {
     var _arr = [];
-    for (var _iterator = arr[Symbol.iterator](), _step; !(_step = _iterator.next()).done;) {
+    for (var val of arr) {
       _arr.push(_step.value);
       if (i && _arr.length === i) break;
     }