Fix.

node_modules/assign-symbols/index.js

@@ -0,0 +1,40 @@
+/*!
+ * assign-symbols <https://github.com/jonschlinkert/assign-symbols>
+ *
+ * Copyright (c) 2015, Jon Schlinkert.
+ * Licensed under the MIT License.
+ */
+
+'use strict';
+
+module.exports = function(receiver, objects) {
+  if (receiver === null || typeof receiver === 'undefined') {
+    throw new TypeError('expected first argument to be an object.');
+  }
+
+  if (typeof objects === 'undefined' || typeof Symbol === 'undefined') {
+    return receiver;
+  }
+
+  if (typeof Object.getOwnPropertySymbols !== 'function') {
+    return receiver;
+  }
+
+  var isEnumerable = Object.prototype.propertyIsEnumerable;
+  var target = Object(receiver);
+  var len = arguments.length, i = 0;
+
+  while (++i < len) {
+    var provider = Object(arguments[i]);
+    var names = Object.getOwnPropertySymbols(provider);
+
+    for (var j = 0; j < names.length; j++) {
+      var key = names[j];
+
+      if (isEnumerable.call(provider, key)) {
+        target[key] = provider[key];
+      }
+    }
+  }
+  return target;
+};