Stops the current task and cleans up, including removing active
            task config file.

            * Raises ``NoActiveTask`` exception if no active task found.

def stop(self):
        """ Stops the current task and cleans up, including removing active
            task config file.

            * Raises ``NoActiveTask`` exception if no active task found.
            """

        self._clean_prior()

        if not self._loaded:
            raise errors.NoActiveTask

        self._clean()