Critical dependency hangup on `npm start`

Disclaimer: I just hijacked the example env hookup since I don't have any of the 

```
WARNING in ./~/airbrake-js/dist/client.js
Critical dependencies:
1:515-522 This seems to be a pre-built javascript file. Though this is possible, it's not recommended. Try to require the original source to get better results.
 @ ./~/airbrake-js/dist/client.js 1:515-522
webpack: bundle is now VALID.
```
