Automatic merge from submit-queue (batch tested with PRs 38788, 38821, 38829)
Node Conformance Test: Fix node conformance test.
The test suite could build on my desktop. However it is failing on jenkins.
https://k8s-gubernator.appspot.com/build/kubernetes-jenkins/logs/ci-kubernetes-node-kubelet-conformance/1
It turns out that `docker save $IMAGE -o $FILE` only works for docker 1.12. (My desktop is 1.12) For older version docker, we should use `docker save -o $FILE $IMAGE instead`. (Jenkins is using 1.9.1)
@timstclair Could you help me review this short PR? :)