Remove the current authenticated user's vote from an issue.

        :param issue: ID or key of the issue to remove vote on

def remove_vote(self, issue):
        """Remove the current authenticated user's vote from an issue.

        :param issue: ID or key of the issue to remove vote on
        """
        url = self._get_url('issue/' + str(issue) + '/votes')
        self._session.delete(url)