Fix the destination path of the resource files

We have namespaced controllers in our ``config/routes.rb``, e.g.
```ruby
namespace :ipv4 do
  resource :addresses
end
```

Controller is named ``Ipv4::AddressesController`` 

swagger-docs saved the resource file as ``api_file_path/addresses.json`` instead of ``api_file_path/ipv4/addresses.json`` so swagger UI threw a 404. This PR addresses that.