test: add tests (#17)

[sinedied]

I've not made it a draft as I want to see it running on CI 😉

[sinedied]

If the CI pass, we can merge this as it still fixes the test config and add some unit tests.
Since the chat API will change anyways, we can add the snapshot tests later after the changes

[isaacs]

npm rm @tapjs/nock
npm i @tapjs/nock@latest

Need to update nock plugin as well as tap itself, or else it dupes @tapjs/core and pulls in the wrong build plugin script.

[sinedied]

I forgot about that one, probably the lack of sleep 😅
It's all fixed now, thanks a lot @isaacs for looking into it!