Fix Job and scheduler

Author: yukithm

job.go

@@ -1,7 +1,7 @@
 package mmbot
 
 // JobFunc is job action function.
-type JobFunc func(*Robot) error
+type JobFunc func(*Robot)
 
 // Job is a scheduled task.
 type Job struct {

robot.go

@@ -56,6 +56,7 @@ func (r *Robot) runLoop() {
 		go r.startServer()
 	}
 	go r.startClient()
+	r.startScheduler()
 
 	receiver := r.Client.Receiver()
 	for {