Another rust-lang gRPC implemention

Why

I think Actor Concurrency Model will be another good choose for Distributed Systems. And the gRPC network framework has became more and more popular. So let's keep an eye on the combination of both, maybe it will be interesting!

Inspired

• gRPC an open-source rpc framework contributed by Google.
• tower-grpc A gRPC implemention with rust-lang.
• actix A fast actor framework for rust-lang.