Uncommented get_ack_version to function properly.

Now pre_flight_check() is the first function to call from ack_cli. To check
all hosts have the ACK installed.
Merge pull request #66 from bpwook/pre-flight

Uncommented get_ack_version to function properly.
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.