Added test cases to verify gateway and MAC addres.
Added test cases to verify gateway and MAC addres.

Added Test Cases:
    - Get Gateway Address And Verify
    - Get MAC And Verify

Resolves openbmc/openbmc-test-automation#1603

Tested: On latest Master build.

Change-Id: If2a49ecfcc8b12b7a8f252c5f7d4fca15d5a8703
Signed-off-by: Prashanth Katti <def1213b2b853506bc42999227c7ced90b83bfd2@in.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation