Allow client-side streaming communication

[ssm951]

Thanks for the work on this proxy! I'm wondering if there is any example of client-side streaming implemented with this proxy. So far, I was able to send all the client-streaming messages to the server perfectly. However, grpc-gateway's generated code expects some EOF before moving on to CloseAndRecv(), so I currently cannot get the server to return the message response.

I'm wondering if there is any examples of triggering the EOF to allow client-side (not bidi) streaming with the server, or if this package would require modification to make this work.