P1 - Will need a unified framework to do integration test in jenkins

[xudifsd]

There are more and more integration test fail found during the release process, we will need to define more test cases to be ran during jenkins integration test, for example #2447 case can be written in script, and can be found before merge.

Before adding test cases, I think we may need to define a framework to make it easy to define and run integration test cases. i.e. set an standard environment, how to do tear down, etc.

[fanyangCS]

deferred to pure k8s version.

[abuccts]

In #4035, Jenkins test scripts have been moved from host to tests/jenkins/ path in repo.
More CI test cases could be added in stage_test.sh file easily in the future.

[fanyangCS]

#4119