Travisdouce/do not return active model serializer json

We should probably create a `RemoteFactoryGirlHomeRails::Serializer` class that provides an interface for the serialization. Something like:

```ruby
module
  class Serializer
    def self.serialize(resource)
       resource.attributes
    end
  end
end
```

This would encourage any users of the gem who want to provide any custom serializations to use this class rather than redefining `#to_json` on all their apps resources/models.