Currently it just prints WebSockets messages as they arrive, never sending any.
In a follow-up I'd like to do that, and also start to use this to figure out
where and how our WebSockets client can be improved.
https://github.com/square/okhttp/issues/2902
This includes everything but character encoding. The implementation
is built around one oversized method that runs top to bottom; I found
this was easier to follow than the switch statement recommended by the
URL standard.
* Add checkstyle and correct anything that failed.
* Expand README.md to have more info for the upcoming release.
* Resolve plugin warnings in pom.xml.