amqp client implementation using tokio

This project are based on RabbitMQ amqp client protocols specs. Support for amqp 1.0 will be implemented later (this could be implemented in different crates).

I'm trying hard to implement the spec from RabbitMQ as match as possible.

There are several checks that you can enable that respect from actual specs. You could enable this by enabling feature flag runtime_check.

By implementing amqp client in tokio, we could switch from async and sync implementation easily by unwrapping the future itself. Having this aside, several implementation defaults will be async, ex: consumer section.

[-] Implement and document the amqp protocols based on traits. [-] Implement connection & channel pools. [-] Implement the wire protocols using tokio-proto. [-] Create several tests based on the specs.