Config paths for modules are not used in the digestify_and_compress task.

Ash has the following configuration in `requirejs.yml`:

```yaml
modules:
  - name: 'pokemons'
  - name: 'pikachu'
  - name: 'charizard'
paths:
  pikachi: 'monsters/pikachu'
  cahrizard: 'monsters/charizard'
```

Ash runs the `assets:precompile` task on his `pokemon` project, he gets an error:
```
Requirejs::BuildError: Cannot compute digest for missing asset: /home/ash/workspace/pokemon/tmp/requirejs/dst/pikachu
````

He expects that the `pikachu` and `charizard` modules are in `/home/ash/workspace/pokemon/tmp/requirejs/dst/monsters/pikachu` and `/home/ash/workspace/pokemon/tmp/requirejs/dst/monsters/charizard` respectively.
He suspects that the `digestify_and_compress` rake task is not using the `paths` in the config.