Fix 404 error of angular-route source map.

This commit fixes a 404 error that happens when the application is loaded and the browser tries to fetch "/dist/angular-route.min.js.map".

I'm not sure this is the *best* way to fix the error, but the other alternative, I think, would be to manually edit `src/lib/angularjs/angular-route.min.js` and delete the [reference to the source map](https://github.com/lmenezes/elasticsearch-kopf/blob/master/src/lib/angularjs/angular-route.min.js#L15), which seemed worse.

The files added were fetched from the [1.3.0 release files](https://code.angularjs.org/1.3.0/).