Train on examples and export the updated model weights.

def main(argv):
    """Train on examples and export the updated model weights."""
    tf_records = argv[1:]
    logging.info("Training on %s records: %s to %s",
                 len(tf_records), tf_records[0], tf_records[-1])
    with utils.logged_timer("Training"):
        train(*tf_records)
    if FLAGS.export_path:
        dual_net.export_model(FLAGS.export_path)
    if FLAGS.freeze:
        if FLAGS.use_tpu:
            dual_net.freeze_graph_tpu(FLAGS.export_path)
        else:
            dual_net.freeze_graph(FLAGS.export_path)