Add UTs for Felix per-port status writing function.
Add UTs for Felix per-port status writing function.

Metaswitch/calico,neiljerram/felix,TrimBiggs/calico,matthewdupre/felix,neiljerram/felix,matthewdupre/felix,alexhersh/calico,TrimBiggs/calico,neiljerram/felix,Metaswitch/calico,alexhersh/calico,neiljerram/felix