Update Knative support for Knative 0.8

[richarddli]

Knative just checked in a change, slated for 0.8 where they have switched from ingresses.networking.internal.knative.dev/ClusterIngress -> ingresses.networking.internal.knative.dev/Ingress. The only difference is that ingresses.networking.internal.knative.dev.Ingress is namespace-scoped.

[kflynn]

This turns out to be a bigger deal than expected. In Knative 0.7.1, you're supposed to "reconcile" Knative ClusterIngress objects to let Knative know that all is well, but Knative would route traffic without reconciliation.

In Knative 0.8.0, no traffic will be routed without marking the Knative Ingress objects as reconciled.

[kflynn]

Shipped in 0.76.0.