Add testing for `SyncServicePort`
Add testing for `SyncServicePort`

TestSyncServicePort does the following:

1. Setup any preexisting objects (tc.setup) that should exist in the
   mocked GCE.
2. Run one sync given a ServicePort.
3. Attempt to re-run the sync with the same ServicePort, checking that
   no update will be needed.

kubernetes/ingress-gce,kubernetes/ingress-gce