track down flaky travis

Travis periodically flakes out on me in hack/test-cmd.sh on the cancel-build step with a message like:
```F1210 16:03:37.203456    5052 helpers.go:21] No such pod: data of kind 'PodList', obj of type 'Pod'```

I'm trying to track it down, so I'll need something to kick travis several times.

For example: https://travis-ci.org/openshift/origin/jobs/43612890, https://travis-ci.org/openshift/origin/jobs/43634629, https://travis-ci.org/openshift/origin/builds/43634549, and that's just today...