Fix TwelveTermToEightTermTest and add missing test cases
Fix TwelveTermToEightTermTest and add missing test cases

scikit-rf/scikit-rf,Ttl/scikit-rf,Ttl/scikit-rf,scikit-rf/scikit-rf,temmeand/scikit-rf,Ttl/scikit-rf,Ttl/scikit-rf,temmeand/scikit-rf,temmeand/scikit-rf,jhillairet/scikit-rf,jhillairet/scikit-rf,jhillairet/scikit-rf