Create package and upload it to NApps Server.

        Raises:
            FileNotFoundError: If kytos.json is not found.

def upload(self, *args, **kwargs):
        """Create package and upload it to NApps Server.

        Raises:
            FileNotFoundError: If kytos.json is not found.

        """
        self.prepare()
        metadata = self.create_metadata(*args, **kwargs)
        package = self.build_napp_package(metadata.get('name'))

        NAppsClient().upload_napp(metadata, package)