Upload the napp from the current directory to the napps server.

def upload_napp(self, metadata, package):
        """Upload the napp from the current directory to the napps server."""
        endpoint = os.path.join(self._config.get('napps', 'api'), 'napps', '')
        metadata['token'] = self._config.get('auth', 'token')
        request = self.make_request(endpoint, json=metadata, package=package,
                                    method="POST")
        if request.status_code != 201:
            KytosConfig().clear_token()
            LOG.error("%s: %s", request.status_code, request.reason)
            sys.exit(1)

        # WARNING: this will change in future versions, when 'author' will get
        # removed.
        username = metadata.get('username', metadata.get('author'))
        name = metadata.get('name')

        print("SUCCESS: NApp {}/{} uploaded.".format(username, name))