change logrotate only run when ACK starts for the first time for conf.
Merge pull request #65 from bpwook/logrotate_fix

change logrotate only run when ACK starts for the first time for conf.
Added "skip" as a result of test case.

Now a method can be skippable. Skipped test is not considered as failure.
Now Only relevant offloads are set and verified when tests start.

If GRO offload is in wrong status and fixed then skip the test.