chore(package): update babel-polyfill to version 6.13.0 (#2459)

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -18,7 +18,7 @@
   ],
   "license": "BSD-3-Clause",
   "dependencies": {
-    "babel-polyfill": "6.9.1",
+    "babel-polyfill": "6.13.0",
     "babel-runtime": "6.11.6",
     "bcrypt-nodejs": "0.0.3",
     "body-parser": "1.15.2",