Initial work

this can be tricky since accept header is a list with quality:

https://github.com/pmlopes/yoke/blob/develop/framework/src/main/java/com/jetdrone/vertx/yoke/middleware/YokeRequest.java#L46
https://github.com/pmlopes/yoke/blob/develop/framework/src/main/java/com/jetdrone/vertx/yoke/middleware/YokeRequest.java#L463

You could have a weird accepts like:

text/html q=0.9; application/json

in this case you should reply json if you can since it has higher quality (100%)