Update oobtkube to test leaf keys in arrays

[sfowl]

Draft for now, creating PR to run e2e tests Ready for review

Update for oobtkube script to also test array elements, not just dictionary keys in k8s objects. This replaces the approach of using sed to modify yaml files, instead modifying the nested dict/list objects then writing them to temporary yaml files, later applied with kubectl. Minor related changes include:

• Logfile message tweaks, full paths to leaf keys are now printed, not just the final leaf key
• A small hardcoded delay (1sec) occurs after successful create/replace of k8s objects, to allow for more time for injected commands to run
• k8s object fields beyond spec are now tested, the only top level keys which are skipped are: apiVersion, kind and metadata

[jeremychoi]

LGTM