* Stub in an integration test
This just calls `kn service list` and verifies it doesn't have a
non-zero exit status.
* Build the client in pre_integration_tests
* Need to explicitly build the `kn` client
As opposed to just building the entire repo. That didn't actually
stick a `kn` binary in the root.
* Address code review feedback
Build the client in e2e-tests.sh instead of presubmit-tests.sh, fix a
couple copy/paste places that referred to eventing, remove unnecessary
knative_teardown function.
* Don't attempt to build kn twice
* Turns out pre_integration_tests() is the easiest way to build kn
We don't have any other good hooks at the moment to do something in
`e2e-tests.sh` that runs only once before the test cluster gets setup.
* Update test-infra to use the new cluster_setup function
This updates the version of test-infra to use the new cluster_setup
function added in https://github.com/knative/test-infra/pull/667
It simplifies our e2e setup logic into one place instead of being
split over presubmit-tests.sh and e2e-tests.sh
* Update vendored test-infra as well
* We have to explicitly tell CI to use the vendored modules
* Be a bit more descriptive in the stubbed out integration test