Fix argument and return type for Invoice::setBillingReference()#97
Open
ronaldsgailis wants to merge 2 commits intonum-num:masterfrom 
Open
Fix argument and return type for Invoice::setBillingReference()#97ronaldsgailis wants to merge 2 commits intonum-num:masterfrom 
ronaldsgailis wants to merge 2 commits intonum-num:masterfrom