New Asynchronous Rust client

[Harpo Roeder]

Hello

I have implemented a new Rust client for NSQ. It is to my knowledge the most fully featured Rust client available (after reading through the available clients on crates.io).

The client is fully asynchronous based on the tokio library. It is not totally feature complete, in particular missing snappy compression (requiring additional effort because of the current asynchronous ecosystem).

It is available on github at https://github.com/harporoeder/tokio-nsq and on crates.io at https://crates.io/crates/tokio-nsq

Thanks!