implements Google's Jump Consistent Hash
From the paper "A Fast, Minimal Memory, Consistent Hash Algorithm" by John Lamping, Eric Veach (2014).
[Paper](http://arxiv.org/abs/1406.2294)
Codahale's now archived jumphash [repository](https://github.com/codahale/jumphash) provided some inspiration, but seeing as its now archived, I wanted to produce a 2021 edition Rust crate which accomplishes the same goals.