Cleans up datastore and deletes all information about current round.

def cleanup_datastore(self):
    """Cleans up datastore and deletes all information about current round."""
    print_header('CLEANING UP ENTIRE DATASTORE')
    kinds_to_delete = [u'Submission', u'SubmissionType',
                       u'DatasetImage', u'DatasetBatch',
                       u'AdversarialImage', u'AdversarialBatch',
                       u'Work', u'WorkType',
                       u'ClassificationBatch']
    keys_to_delete = [e.key for k in kinds_to_delete
                      for e in self.datastore_client.query_fetch(kind=k)]
    self._cleanup_keys_with_confirmation(keys_to_delete)