def removeforkrelation(self, project_id):
        """
        Remove an existing fork relation. this DO NOT remove the fork,only the relation between them

        :param project_id: project id
        :return: true if success
        """
        request = requests.delete(
            '{0}/{1}/fork'.format(self.projects_url, project_id),
            headers=self.headers, verify=self.verify_ssl,
            auth=self.auth, timeout=self.timeout)

        if request.status_code == 200:
            return True
        else:
            return False
Remove an existing fork relation. this DO NOT remove the fork,only the relation between them

        :param project_id: project id
        :return: true if success