fix in bower.json 'main' section

Hi,

Using grunt (and grunt-bower-install), when I do some action (build, deploy, serve) that involve the autoinjection of bower components grunt-bower-install injects Autolinker.js wrong:

```
<!-- bower:js -->
...
<script src="bower_components/Autolinker.js/Autolinker.js"></script>
...
<!-- endbower -->
```

The `dist` subdirectory was missing.