tests: print link label in graphviz output
tests: print link label in graphviz output

cben/rhizi,yuvadm/rhizi,cben/rhizi,cben/rhizi,Rhizi/rhizi,ozFri/rhizi,shlomif/rhizi,ozFri/rhizi,ozFri/rhizi,shlomif/rhizi,Rhizi/rhizi,tlevine/rhizi,Rhizi/rhizi,yuvadm/rhizi,tlevine/rhizi,cben/rhizi,ozFri/rhizi,shlomif/rhizi,tlevine/rhizi,shlomif/rhizi,Rhizi/rhizi,tlevine/rhizi,yuvadm/rhizi,yuvadm/rhizi