FYI: cache tests

[mnot]

Just so you know, I've added caddy + cache-handler to https://cache-tests.fyi

Happy to talk through individual tests if there's interest.

[darkweak]

Hey @mnot, thank you for adding Caddy there. I wonder if the default HTTP cache behavior (without any extra configuration) should not store the response if this one doesn't have the Cache-Control HTTP response header.
We will work on the main codebase to support most of the cache-tests test suite.

[mholt]

Thank you Mark! And thanks @darkweak for maintaining this 😊

[Jimbolino]

Thnx, this was really helpful, because i couldn't figure out why my http 400 responses were not cached, even though they contain the right cache headers. Changing them to 404 fixed the issue for me :)