Akka.TestKit.TestProbe can't deliver DeathWatch notifications #2465
Description
The TestProbe, as it is currently implemented, is not capable of signaling to any other actors who have Context.Watch'd it that is Terminated, which in essence means that it violates one of the guarantees actors are supposed to make.
This unit test will fail:
/// <summary>
/// Should be able to receive a <see cref="Terminated"/> message from a <see cref="TestProbe"/>
/// if we're deathwatching it and it terminates.
/// </summary>
[Fact]
public void TestProbe_should_send_Terminated_when_killed()
{
var p = CreateTestProbe();
Watch(p);
Sys.Stop(p);
ExpectTerminated(p);
}