Automatic merge from submit-queue

Print osImage and kubeletVersion for nodes before and after GCE upgrade

This will print, e.g.:
```
== Pre-Upgrade Node OS and Kubelet Versions ==
name: "e2e-test-mtaufen-master", osImage: "Google Container-VM Image", kubeletVersion: "v1.4.5-beta.0.45+90d209221ec8dc-dirty"
name: "e2e-test-mtaufen-minion-group-jo79", osImage: "Debian GNU/Linux 7 (wheezy)", kubeletVersion: "v1.4.5-beta.0.45+90d209221ec8dc-dirty"
name: "e2e-test-mtaufen-minion-group-ox5l", osImage: "Debian GNU/Linux 7 (wheezy)", kubeletVersion: "v1.4.5-beta.0.45+90d209221ec8dc-dirty"
name: "e2e-test-mtaufen-minion-group-qvbq", osImage: "Debian GNU/Linux 7 (wheezy)", kubeletVersion: "v1.4.5-beta.0.45+90d209221ec8dc-dirty"
```

Let me know what output format you prefer and I'll see if I can make it work, I have the extent of flexibility allowed by jsonpath.