Unwatch a user

        :param username: The username you want to unwatch

def unwatch(self, username):

        """Unwatch a user

        :param username: The username you want to unwatch
        """

        if self.standard_grant_type is not "authorization_code":
            raise DeviantartError("Authentication through Authorization Code (Grant Type) is required in order to connect to this endpoint.")

        response = self._req('/user/friends/unwatch/{}'.format(username))

        return response['success']