Negative test for docker flag

subtest...flag: Add new test case for docker flag. To test the invalid docker flags when running a container.
The test result what we expected is the container failed to start with the Warning/Error/Usage output.  If the container can be start and no Warning/Error/Usage output, the test will be FAIL. 
Adding this test will be better to verify the bug https://bugzilla.redhat.com/show_bug.cgi?id=1098267 in the future.

Nancy (Xiaonan He)