pyroute2: use pyroute2's routes handling

Use pyroute2's routes handling instead of ipwrapper.

Change-Id: I8ccc39470ef4094dc0a6a6ca157eb0c5aef05cd1
Signed-off-by: Petr Horáček <phoracek@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/32450
Reviewed-by: Antoni Segura Puimedon <asegurap@redhat.com>
Reviewed-by: Ondřej Svoboda <osvoboda@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>