Test harness tool does not wait for CRDs to be processed

[porridge]

What happened:

https://circleci.com/gh/kudobuilder/kudo/9541 flaked with:

=== RUN   kudo
2020/01/14 14:24:53 CustomResourceDefinition:/instances.kudo.dev created
2020/01/14 14:24:53 CustomResourceDefinition:/operators.kudo.dev created
2020/01/14 14:24:53 CustomResourceDefinition:/operatorversions.kudo.dev created
--- FAIL: kudo (6.48s)
    harness.go:215: Running tests with a mocked control plane (kube-apiserver and etcd).
    harness.go:196: started test environment (kube-apiserver and etcd) in 6.345799792s
    harness.go:412: error creating resource Operator:default/configmap-operator: no matches for kind "Operator" in version "kudo.dev/v1beta1"
    harness.go:461: tearing down mock control plane
FAIL

A retry succeeded.

What you expected to happen:

No failure! The tool should wait for all CRDs to reach usable status before trying to create objects of the newly defined types.

How to reproduce it (as minimally and precisely as possible):

go run ./cmd/kubectl-kudo test many times

[porridge]

Turns out that the tool does wait for CRDs but it does it using a discovery client.

However that's effectively a no-op, since (at least in that particular case) all passed CRD objects fail this type assertion causing this loop to be empty.