put wildcard in asset path

I had a problem where `rake assets:precompile` would put the manifest in public/assets/#{application}/manifest**.json

I dont see a configuration we set to do this but we are using a gem to upload our assets to a CDS that might be doing this.  Because this might be something a library does and could potentially use the name name of the library, the application, or both. I thought a ** would cover all those cases.