Forks a repository within the same project.
        :param project:
        :param repository:
        :param new_repository:
        :return:

def fork_repository(self, project, repository, new_repository):
        """
        Forks a repository within the same project.
        :param project:
        :param repository:
        :param new_repository:
        :return:
        """
        url = 'rest/api/1.0/projects/{project}/repos/{repository}'.format(project=project,
                                                                          repository=repository)
        body = {}
        if new_repository is not None:
            body['name'] = new_repository
        if new_repository is not None:
            body['project'] = {'key': project}
        return self.post(url, data=body)