manage migrate backup_app 0003_auto_20160127_2002

def reverse_func(apps, schema_editor):
    """
    manage migrate backup_app 0003_auto_20160127_2002
    """
    print("\n")
    remove_count = 0
    BackupRun = apps.get_model("backup_app", "BackupRun")
    backup_runs = BackupRun.objects.all()
    for backup_run in backup_runs:
        # Use the origin BackupRun model to get access to get_config_path()
        temp = OriginBackupRun(name=backup_run.name, backup_datetime=backup_run.backup_datetime)
        config_path = temp.get_config_path()
        try:
            config_path.unlink()
        except OSError as err:
            print("ERROR removing config file: %s" % err)
        else:
            remove_count += 1
            # print("%r removed." % config_path.path)

    print("%i config files removed.\n" % remove_count)