Handle thrown exceptions

[1Jajen1]

Right now exception handling in tests is left to the user writing the test and any exception thrown will not be caught. That is fine for most cases (when programming in a functional way and prefering total functions) but it may be a restriction that does not need to be there. Any ideas on how to approach this (if at all) are welcome :)

[1Jajen1]

The plan for now is: Treat all non-io tests as pure (assert that they simply don't throw) and all impure tests should be done in io (which will later be replaced by suspend to conform with arrow-fx). This also means that the result checking in state-machine tests will get a Either<Throwable, R> instead of just an R to properly test exceptions there.