Add a version flag.

  extends: .install-wheel

  script:

    - template --help

    - template --version

test:

  stage: test

        help="Output to filename",

        type=argparse.FileType("w"),

    )

    parser.add_argument(

        "-V",

        "--version",

        help="Template version",

        action="store_true",

    )

    args = parser.parse_args()

    if args.version:

        print("Template version {}.".format(__version__))

    infd = args.filename if args.filename else sys.stdin

    outfd = args.output if args.output else sys.stdout

    print(render(infd.read()), file=outfd)