update

.babelrc

@@ -1,3 +1,12 @@
 {
-  "presets": ["es2015", "stage-2"]
+  "presets": ["es2015", "stage-2"],
+  "plugins": [[
+    "transform-runtime",
+    {
+      "helpers": false,
+      "polyfill": false,
+      "regenerator": true,
+      "moduleName": "babel-runtime"
+    }
+  ]]
 }

package.json

@@ -5,6 +5,7 @@
   "devDependencies": {
     "body-parser": "^1.13.2",
     "babel-cli": "^6.24.1",
+    "babel-plugin-transform-runtime": "^6.23.0",
     "babel-preset-es2015": "^6.24.1",
     "babel-preset-stage-2": "^6.24.1",
     "express": "^4.13.1",