Individual files contain the following tag instead of the full license text.

    This file is part of the pycalver project
    https://gitlab.com/mbarkhau/pycalver

    Copyright (c) 2019 Manuel Barkhau (mbarkhau@gmail.com) - MIT License
    SPDX-License-Identifier: MIT

This enables machine processing of license information based on the SPDX
License Identifiers that are here available: https://spdx.org/licenses/