add compare check for example outputs

[mjreno]

Basic testing for examples:

• compare standard budget, binary grid and head files to example output
• add standards under test/__compare__/test_examples with the example name as file stem name
• first step baseline sanity checks for full examples

[wpbonelli]

looks good to me, did you find it was easier to just manually compare than use the snapshot fixtures for now?

[mjreno]

looks good to me, did you find it was easier to just manually compare than use the snapshot fixtures for now?

I had some cross platform failures with the npy files, similar to what you've mentioned. I tried using pytest.approx, which adds tolerances to the files once regenerated (this made lots of snapshot files) but it didn't address the failures. I wasn't sure about support for other file types (like json would be good for the gdb checks)- anyways it can go in any sensible direction from here but this was just a straight forward way to get some basic sanity checks in.