Configure koppie to use Hyrax::ValkyriePersistDerivatives
user
```ruby
ActiveSupport::Reloader.to_prepare do
  Hydra::Derivatives.config.output_file_service = Hyrax::ValkyriePersistDerivatives
  Hydra::Derivatives.config.source_file_service = Hyrax::LocalFileService
end
```
assistant