v5.1.0 6th January 2020
  - Added the 'minimum-glibc-version' project option to specify the minimum
    GLIBC version required by the project.  This is used to determine the
    correct platform tag to use for Linux wheels.
  - Added the 'build-tag' project option to specify the build tag to be used in
    the name of a wheel.  sip-wheel has a corresponding '--build-tag' command
    line option.
  - The values of list options in pyproject.toml files can now contain
    environment markers as defined in PEP 508.
  - Added Project.project_path() to the API.

v5.0.1 19th December 2019
  - Bug fixes.

v5.0.0 4th October 2019
  - The release of SIP v5.
