[feature] Suppory unit test by providing handlers for updateStatus and DeleteJob

[gaocegege]

    // TODO(ChanYiLin): these are originally for testing, but with using common library,
    // we can not replcae the function. Also need to update or remove some tests

    // tc.updateStatusHandler = tc.UpdateJobStatusInApiServer
    // set delete handler.
    // tc.deleteTFJobHandler = tc.DeleteJob

It will be better to have such handlers to replace them when running test cases.

/cc @ChanYiLin

[ChanYiLin]

Thanks for the reminder, I'll take this issue.

[ChanYiLin]

/assign @ChanYiLin