fix(babel-helpers): changed the build to expect external-helpers

Author: travi

README.md

@@ -16,6 +16,9 @@
 $ npm install @travi/hapi-react-router -S
 ```
 
+:warning: this plugin expects [external babel-helpers](https://babeljs.io/docs/plugins/external-helpers/)
+to be provided by the consumer
+
 ### Register with your [Hapi](https://hapijs.com) v17 server
 
 Include this plugin in the [manifest](https://github.com/hapijs/glue) of your

rollup.config.js

@@ -15,7 +15,8 @@ export default {
     babel({
       babelrc: false,
       exclude: ['./node_modules/**'],
-      presets: [['travi', {targets: {node: 8, browser: true}, react: true, modules: false}]]
+      presets: [['travi', {targets: {node: 8, browser: true}, react: true, modules: false}]],
+      plugins: ['external-helpers']
     })
   ],
   output: [