Send an user_dict to NApps server using POST request.

        Args:
            user_dict(dict): Dictionary with user attributes.

        Returns:
            result(string): Return the response of Napps server.

def register(self, user_dict):
        """Send an user_dict to NApps server using POST request.

        Args:
            user_dict(dict): Dictionary with user attributes.

        Returns:
            result(string): Return the response of Napps server.

        """
        endpoint = os.path.join(self._config.get('napps', 'api'), 'users', '')
        res = self.make_request(endpoint, method='POST', json=user_dict)

        return res.content.decode('utf-8')