Akka.Streams.TestKit 1.3.8

Maintenance Release for Akka.NET 1.3** Akka.NET v1.3.8 is a minor patch consisting mostly of bug fixes as well as an upgrade to DotNetty v0.4.8. DotNetty v0.4.8 Upgrade** You can [read the release notes for DotNetty v0.4.8 here](https://github.com/Azure/DotNetty/blob/5eee925b7597c6b07689f25f328966e330ff58f9/RELEASE_NOTES.md) - but here are the major improvements as they pertain to Akka.NET: 1. DotNetty length-frame decoding is now fully-supported on .NET Core on Linux and 2. Socket shutdown code has been improved, which fixes a potential "port exhaustion" issue reported by Akka.Remote users. If you've been affected by either of these issues, we strongly encourage that you upgrade your applications to Akka.NET v1.3.8 as soon as possible. Updates and Additions** 1. [Akka.Streams: add PreMaterialize support for Sources](https://github.com/akkadotnet/akka.net/pull/3476) 2. [Akka.Streams: add PreMaterialize support for Sinks](https://github.com/akkadotnet/akka.net/pull/3477) 3. [Akka.Streams: Port Pulse, DelayFlow and Valve streams-contrib stages](https://github.com/akkadotnet/akka.net/pull/3421) 4. [Akka.FSharp: Unit test Akka.FSharp.System.create with extensions](https://github.com/akkadotnet/akka.net/pull/3407) Relevant documentation for Akka.Streams pre-materialization, for those who are interested: http://getakka.net/articles/streams/basics.html#source-pre-materialization Bugfixes** 1. [Akka.Remote: ActorSelection fails for ActorPath from remotely deployed actors](https://github.com/akkadotnet/akka.net/issues/1544) 2. [Akka.Remote: WilcardCard ActorSelections that fail to match any actors don't deliver messages into DeadLetters](https://github.com/akkadotnet/akka.net/issues/3420) 3. [Akka.Cluster: SplitBrainResolver logs "network partition detected" after change in cluster membership, even when no unreachable nodes](https://github.com/akkadotnet/akka.net/issues/3450) 4. [Akka: SynchronizationLockException in user-defined mailboxes](https://github.com/akkadotnet/akka.net/issues/3459) 5. [Akka: UnhandledMessageForwarder crashes and restarted every time the app is starting](https://github.com/akkadotnet/akka.net/issues/3267) | COMMITS | LOC+ | LOC- | AUTHOR | | --- | --- | --- | --- | | 17 | 498 | 171 | Aaron Stannard | | 4 | 1054 | 23 | Bartosz Sypytkowski | | 2 | 2 | 2 | Fábio Beirão | | 2 | 16 | 2 | Aaron Palmer | | 1 | 1063 | 4 | Oleksandr Bogomaz | | 1 | 1 | 1 | Ismael Hamed | | 1 | 1 | 1 | Gauthier Segay |