Invoke OpenShift 3 tests so artifacts can be downloaded

Depends on https://github.com/openshift/origin/pull/331
I'm not sure you want to have everything from `/tmp/origin/e2e` since base on this you'll have there etcd data, volume data and log dir see [these lines](https://github.com/openshift/origin/blob/master/hack/test-end-to-end.sh#L24-L26). And we just want logs, right?