Refactor tests with purescript-quickcheck and spec #5
Description
QuickCheck is a property-based testing library which was originally written in Haskell, but which has been ported to PureScript.
QuickCheck works by generating random data with which to test your properties. This allows us to gain confidence that the properties hold, as more and more randomly-generated tests are run.
It would be great to refactor the current tests to it.