Added new unit testcases

1. Added testcases to validate IP/PrefixLengnth/MACAddress.
2. Added test to rtnetlink.

Resolves openbmc/openbmc#2546

Change-Id: I61efbf69682a50f7479b68e32d9714e9c81a32d7
Signed-off-by: Nagaraju Goruganti <ngorugan@in.ibm.com>
5 files changed