Remove recurrence validate function since it is not being used and is being tracked already as an issue
Remove recurrence validate function since it is not being used and is being tracked already as an issue

node-schedule/node-schedule,santigimeno/node-schedule,tempbottle/node-schedule,bbqsrc/node-schedule,pdilyard/node-schedule,tejasmanohar/node-schedule,BirdEggegg/node-schedule,seripap/node-schedule,andy-g/node-schedule