bower nests jquery in a 'dist' folder, initial grunt build fails

On a plain vanilla install (after `npm install`, `bower install`, and during the initial run of `grunt`), the requirejs grunt task produces an error:

```
Running "requirejs:release" (requirejs) task
Error: ENOENT, no such file or directory '~/backbone-boilerplate/dist/vendor/bower/jquery/jquery.js'
```
...because inside the vendor directory, jquery.js is nested in a `dist` directory.