created a super minimal mash function for sketching sequences.

[TimothyStiles]

This package is meant to help create "sketches" via the mash sketching algorithm. There's plenty of room for optimization here but I've implemented the core idea.

Mash: fast genome and metagenome distance estimation using MinHash.

Ondov, B.D., Treangen, T.J., Melsted, P. et al. Genome Biol 17, 132 (2016). https://doi.org/10.1186/s13059-016-0997-x

Mash Screen: high-throughput sequence containment estimation for genome discovery.

Ondov, B., Starrett, G., Sappington, A. et al. Genome Biol 20, 232 (2019). https://doi.org/10.1186/s13059-019-1841-x

[Koeng101]

[TimothyStiles]

adding the help wanted tag because @Koeng101 wants this merged but the following still needs to be done and I won't be able to get around to it for at least a week.

1. Keep hashes sorted for faster search
2. Figure out where this belongs on the package level e.g seqhash or maybe a new search package?
3. Better comments and docs in general
4. 100% test coverage and more robust test case.

[carreter]

Linking this to #356

[Koeng101]

I really like @soypat changes in this case. They make a lot of sense to me