Injecting `Unconfined` in tests generally seems to be a good idea

# coroutines

[Paul Woitaschek]

Injecting Unconfined in tests generally seems to be a good idea

[dave08]

If you're on jvm, you could use runBlocking and join or await to test concurrent code using the CommonPool, otherwise the test finishes before the result... in your case you were comparing to rx with no scheduler, and in the reactive guide it says Unconfined is the most similar to that...