Changed

• Update tokio-util dependency to 0.3, FramedWrite trait bound is changed. #365
• Only poll dropped ContextFut if event loop is running. #374
• Minimum Rust version is now 1.40 (to be able to use #[cfg(doctest)])

Fixed

• Fix ActorFuture::poll_next impl for StreamThen to not lose inner future when it's pending. #376