* Some `TestAdapter` methods are creating task continuations of `Task<Task>`, but were not using `.Unwrap()` and so exceptions that might have been thrown by the result `Task` were not being surfaced correctly.
 * Instead of testing `.IsFaulted` and throwing an `Exception` that wraps the antecedent `Tasks` exception manually, just use `Task::Wait` to observe the original exception and naturally propagate that up the chain.
 * Add test that simulates an exception being thrown from `Bot::OnReceive` so we have proper coverage of that scenario.