Upgrade to latest netty (Netflix#1789)

* Bump to latest netty

* genlock

Bump version

Fix case of MaxRequestsPerConnection (Netflix#1785)

Downgrade gradle and netflixoss so it works with netty classifiers again

integration test: jumbo origin response (Netflix#1676)

Release 2.3.0

[zuul-core] Remove deprecated port attrs. Use `_ADDRESS` instead.

Merge pull request Netflix#898 from Netflix/revert-ribbon

Downgrade ribbon to fix proxying

Release 2.1.8

Release v2.1.7