New version
    
    - Allow building libbytesize without Python 2 support (vtrefny)
    - Sync spec with downstream (vtrefny)
    - Add gcc to BuildRequires (vtrefny)
    - Fix links for documentation and GH project (vtrefny)
    - Add a HACKING.rst file (vpodzime)
    - Do not segfault when trying to bs_size_free NULL (vtrefny)