Ossaudit

- Skip duplicate packages in the requirement files.

- Add support for ignoring vulnerabilities by ID.
- Expose all configuration options as command-line arguments.
- Change `--config-file` to `--config`.
- Show all columns as text to avoid inaccurate formatting of certain
version numbers.
- Always print a summary that shows the number of audited packages.

- Add support for customized columns.
- Add help strings for `--help`.
- Exit with non-zero status code if any vulnerabilities are found.

- Add support for authenticated requests.
- Use platform-specific storage paths.
- Fix bug that caused invalid cache misses.

- Initial release.