Fix.

node_modules/is-number/index.js

@@ -0,0 +1,22 @@
+/*!
+ * is-number <https://github.com/jonschlinkert/is-number>
+ *
+ * Copyright (c) 2014-2015, Jon Schlinkert.
+ * Licensed under the MIT License.
+ */
+
+'use strict';
+
+var typeOf = require('kind-of');
+
+module.exports = function isNumber(num) {
+  var type = typeOf(num);
+
+  if (type === 'string') {
+    if (!num.trim()) return false;
+  } else if (type !== 'number') {
+    return false;
+  }
+
+  return (num - num + 1) >= 0;
+};