Add some HPACK integration tests.
Add some HPACK integration tests.

irvind/hyper,lawnmowerlatte/hyper,lawnmowerlatte/hyper,irvind/hyper,plucury/hyper,Lukasa/hyper,jdecuyper/hyper,masaori335/hyper,masaori335/hyper,Lukasa/hyper,fredthomsen/hyper,fredthomsen/hyper,plucury/hyper,jdecuyper/hyper