Links are causing issues in development mode..

A Warning is visible... It works, but this is not nice.

```index.js:151 External link authors/jeroen was detected in a Link component. Use the Link component only for internal links. See: https://gatsby.dev/internal-links
```

<img width="924" alt="Screenshot 2019-04-29 at 11 33 43" src="https://user-images.githubusercontent.com/10019/56887814-d4c4e400-6a72-11e9-88e7-2f8e1eb94357.png">