Read billing url from config and add to API
Read billing url from config and add to API

no issue

TryGhost/Ghost,ErisDS/Ghost,janvt/Ghost,TryGhost/Ghost,bitjson/Ghost,JohnONolan/Ghost,kevinansfield/Ghost,bitjson/Ghost,TryGhost/Ghost,e10/Ghost,e10/Ghost,kevinansfield/Ghost,ErisDS/Ghost,ErisDS/Ghost,JohnONolan/Ghost,kevinansfield/Ghost,JohnONolan/Ghost,janvt/Ghost