Port Akka.Tests.Pattern tests to async/await - CircuitBreakerSpec#5830

Aaronontheweb merged 2 commits intoakkadotnet:feature/async_testkitakkadotnet/akka.net:feature/async_testkitfrom

Arkatufus:async_testkit/Akka.Tests.Pattern.CircuitBreakerSpecArkatufus/akka.net:async_testkit/Akka.Tests.Pattern.CircuitBreakerSpecCopy head branch name to clipboard