Ookami

Make mix fail when make fails

1

When `make` fails with a compile error or similar, `mix test` just keeps on trucking, using the old executable. This annoys me.

A bit neater than having to use the Github version. Make sure documentation can be generated and looks good.

Hamming distance tests could use some love. At least make sure the tests hit all edge cases. Perhaps do exhaustive testing on ultra-short hashes (8 bits? 16 bits?)