Merge pull request #454 from Covertness/master

add coap crate

README.md

@@ -923,6 +923,8 @@ See also [About Rust’s Machine Learning Community](https://medium.com/@autumn_
   * [meqif/rust-utp](https://github.com/meqif/rust-utp) — a [uTP](http://www.bittorrent.org/beps/bep_0029.html) (Micro Transport Protocol) library for Rust. [<img src="https://api.travis-ci.org/meqif/rust-utp.svg?branch=master">](https://travis-ci.org/meqif/rust-utp)
 * ZeroMQ
   * [erickt/rust-zmq](https://github.com/erickt/rust-zmq) — [ZeroMQ](http://zeromq.org/) bindings [<img src="https://api.travis-ci.org/erickt/rust-zmq.svg?branch=master">](https://travis-ci.org/erickt/rust-zmq)
+* CoAP
+  * [Covertness/coap-rs](https://github.com/Covertness/coap-rs) — A [Constrained Application Protocol(CoAP)](https://tools.ietf.org/html/rfc7252) library for Rust. [<img src="https://api.travis-ci.org/Covertness/coap-rs.svg?branch=master">](https://travis-ci.org/Covertness/coap-rs)
 
 
 ### Parser