Get end to end tests running against PRs

[bobcatfish]

Expected behavior

Every PR should have all end to end tests (i.e. tests in the test dir which use the e2e build label) executed against it.

Actual behavior

We don't have any code, or any automation :O

Additional info

• This is the config for the Pipeline end to end tests which are called "integration tests" in this config <-- for now we should probably just copy this and do exactly what it does
• The config that prow uses to determine what to run against what repo is in this config.yaml and the instructions for updating it are in this readme (you might need the assistance of someone with cluster access to apply the config)

[vtereso]

Thanks again to @vdemeester for setting this up here

[ncskier]

Closing this issue because of the previous comment, and PR #18 adds a basic e2e test for ko apply -f config/