Clear task output: remove value ``budget_inflation_adjusted`` from all :class:`Movie` objects.

def clear(self):
        """Clear task output: remove value ``budget_inflation_adjusted`` from all :class:`Movie` objects.
        """
        self.mark_incomplete()
        session = client.get_client().create_session()

        movies = session.query(models.Movie)
        movies.update({'budget_inflation_adjusted': None})

        session.commit()
        session.close()