zebra-puzzle: add canonical data

[HarrisonMc555]

Closes #592

There isn't much to do on this one since there's only one static answer. But I figured I would include it for completeness.

[Insti]

Comment not directly related to the PR:

This exercise does not seem like a good Exercism problem.

[ErikSchierboom]

@Insti Test-wise it is indeed not a great fit, although the problem itself is brilliant, as it forces you to prune a rather large search space. I've seen lots of interesting submissions.

I think we could perhaps improve this exercise by adding intermediate tests for some of the properties that should hold.

[Insti]

Should the properties be: 'drinks_water' and 'owns_zebra' ?

[HarrisonMc555]

I was thinking that this would be the return "type" of the expected value. If we do adjust the exercise to use different clues, then this would be a good way to know what data "type" the exercise would be testing for. Or would this not be a good use of the "property" tag? We could alternatively use "nationality", etc. as the key instead of "expected".

[Insti]

But we're always asking for nationality. How does the test generator know whose nationality we want?

If the exercise changes, the test data will also need to change so I would not worry about future proofing at this stage.

[HarrisonMc555]

Oh I understand now. And yes, good point. Changing now.

[Insti]

@Insti Test-wise it is indeed not a great fit, although the problem itself is brilliant, as it forces you to prune a rather large search space. I've seen lots of interesting submissions.

I must admit that I've not tried to solve it myself.

Would it be possible to formulate a (or n) different set(s) of clues that the same solver could use in order to have test cases that couldn't be passed just by returning static values?

[ErikSchierboom]

Good question. I have to think about it.

[HarrisonMc555]

I don't believe I have write access to this repository, so I can't merge this. Does somebody want to merge for me? Thanks 😄

[HarrisonMc555]

Let me know if you want me to squash or if you want to do a squash on merge.

[jpreese]

You're all set @HarrisonMc555