Update check https cert

[pgporada]

Pull Request Checklist

Is this in reference to an existing issue? No it is not

General

• [X] Update Changelog following the conventions laid out on Keep A Changelog

• [X] Update README with any necessary configuration snippets

• [ ] Binstubs are created if needed

• [X] RuboCop passes

• [X] Existing tests pass

New Plugins

Technically this is an upgrade to a plugin that didn't have tests. There are now tests.

• [X] Tests

• [X] Add the plugin to the README

• [X] Does it have a complete header as outlined here

Purpose

I need to check that a certificate is correctly and successfully expired. Basically the opposite of what the standard check-https-cert.rb is used for.

Known Compatablity Issues

[pgporada]

Hmm.. that commit history is old and wonky. I'll clean it up.