* Add Istio client from knative/serving
- Add Istio types in 'apis/istio/v1alpha3'
- Update codegen scripts
- Generate client in 'client'
- Add @tcnghia as owner for 'apis/istio'
Fixes#1
* nix linguring serving package dep
* cleanup vendor cache
* Mark /client as generated
* Fix verify-codegen script
* Run verify-codegen.sh via presubmit-tests.sh
* Remove Gatewaies -> Gateway hack
Looks like we don't need it anymore
Scott Andrews