Look into porting test.check.random

[steos]

Since the initial port test.check has changed the RNG from java.util.Random to an immutable version of java.util.SplittableRandom. https://github.com/clojure/test.check/blob/000000076395383d824ec8a468a88ee2baa6f121/src/main/clojure/clojure/test/check/random.clj