Log Message:
archivers/ruby-ffi-libarchive: update to 1.0.3

Update ruby-ffi-libarchive to 1.0.3.

1.0.3 (2020-06-26)

* Optionally clone entries when iterating through an archive #30 (jatoben)
* Replace specific types with more generic equivalents. #32 (phiggins)
* Modern expeditor / buildkite setup #33 (tas50)