Fix CVE command injection

[tomtaylor]

• Use Open3 to prevent command injection, fixing https://github.com/affix/CVE-2022-36231
• Fix Title metadata
• Fix tests

[tomtaylor]

I currently am the only owner of this Rubygem, but am unable to write to this repo since leaving Newspaper Club many years ago. I'd like to get this fix merged and released and transfer ownership to someone who can manage this project. Is that you @Michael-Kurt or @jaisoncoelho? If not, I'll fork the repo.

[Michael-Kurt]

Hi @tomtaylor! You can assign that PR/fix to @jaisoncoelho for review and merge. Thanks for reaching out.

[tomtaylor]

Thanks @Michael-Kurt - unfortunately I'm not able to assign anything in this repo.

[Michael-Kurt]

No problem. I will assign it. Thanks @tomtaylor

[jaisoncoelho]

@tomtaylor I'd like to thank you for let us aware regarding the CVE.
We'd like to get responsible for the gem available on RubyGems (https://rubygems.org/gems/pdf_info). Let us know if it sounds good to you, and then we can proceed with the repository transfer.