v0.0.21

Changed

• The CLI entrypoint is now pypi-attestations
  (#82)
• The CLI verify subcommand has been changed to verify attestation,
  as in pypi-attestations verify attestation --identity ...
  (#82)

Added

• The CLI has a new subcommand verify pypi, which takes a URL to a
  PyPI distribution (either a wheel or a source distribution) and a
  GitHub/GitLab repository. The command verifies the distribution by
  downloading it and its provenance from PyPI, verifying them using
  sigstore and checking that the repository matches the one in the
  PyPI provenance file.
  (#82)