test_util.py: generate_random_RZDoc: make rzdoc_name optional
test_util.py: generate_random_RZDoc: make rzdoc_name optional

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