Function jump_hash_from_u64 

pub fn jump_hash_from_u64(key: u64, buckets: u32) -> u32

hashes a u64 to a u32 which is in the range of 0..buckets

expects a number of buckets greater than zero

use jumpconsistenthash::jump_hash_from_u64;
//the bucket hashed should always be less than the number of buckets
let number_of_buckets = 10;
let bucket = jump_hash_from_u64(52, number_of_buckets);
assert!(bucket < number_of_buckets);