Certainly more secure!

• Use paragonie/certainly to fetch a new cacert.pem if necessary (saves us from having to unset the 'verify' flag on Guzzle)

• A slight bit of refactoring just to make things prettier

Something new, something... old, but new. Huh?

• Preserve old input on validation failure
• Add a few extra validation checks
• Change up the wording a little on the home page.

Initial release

Hooray!