Support clojure 1.10.1

[dparis]

• Update clojure dependency to latest stable version 1.10.1
• Update :spec-provider.stats/distinct-values spec to conform to most recent spec function specs

The distinct-values spec was using (s/* any?) to validate what appears to always be a set. This commit changed the s/* function to validate that each spec passed is either nil? or sequential?: https://github.com/clojure/spec.alpha/commit/3b34bd32457c42bfea828bdaf4d80a108997247d A set is not sequential so this was failing. On the assumption that distinct-values is always a set, I've updated the spec to instead check for a set collection containing unique elements that all conform to any?.

Let me know if you'd like me to change anything here. If the assumption that distinct-values is always supposed to be a set is invalid, happy to update the spec accordingly.

[robhanlon22]

Resolves #28.

[stathissideris]

Merged, many thanks