Fix.

node_modules/is-plain-object/index.js

@@ -0,0 +1,37 @@
+/*!
+ * is-plain-object <https://github.com/jonschlinkert/is-plain-object>
+ *
+ * Copyright (c) 2014-2017, Jon Schlinkert.
+ * Released under the MIT License.
+ */
+
+'use strict';
+
+var isObject = require('isobject');
+
+function isObjectObject(o) {
+  return isObject(o) === true
+    && Object.prototype.toString.call(o) === '[object Object]';
+}
+
+module.exports = function isPlainObject(o) {
+  var ctor,prot;
+
+  if (isObjectObject(o) === false) return false;
+
+  // If has modified constructor
+  ctor = o.constructor;
+  if (typeof ctor !== 'function') return false;
+
+  // If has modified prototype
+  prot = ctor.prototype;
+  if (isObjectObject(prot) === false) return false;
+
+  // If constructor does not have an Object-specific method
+  if (prot.hasOwnProperty('isPrototypeOf') === false) {
+    return false;
+  }
+
+  // Most likely a plain Object
+  return true;
+};