Locations

Based on the idea that http://gaudi-cdn-test.s3.amazonaws.com/apps/simpleumdapp/undefined/app.js takes you to the file on amazonaws

it returns the link up until the filename, when you append a filename to that url you'll see the content of that file.
I think the API could be simple if we have the main exported function return a stream that also has a `getLocation()` method.  E.g.:

```javascript
var publisher = require('gulp-frau-publisher')(options);
...
var appconfig = buildAppconfig( publisher.location );
...
gulp.src('dist/**').pipe( publisher );
...
```