List all tags made on this project.
        :param pattern: filters the starting letters of the return value
        :return:

def list_tags(self, pattern=None):
        """
        List all tags made on this project.
        :param pattern: filters the starting letters of the return value
        :return:
        """
        request_url = "{}tags".format(self.create_basic_url())

        params = None
        if pattern:
            params = {'pattern': pattern}

        return_value = self._call_api(request_url, params=params)
        return return_value['tags']