added Cron.Jobs() method

tools/cron/job.go

@@ -0,0 +1,25 @@
+package cron
+
+// Job defines a single registered cron job.
+type Job struct {
+	fn       func()
+	schedule *Schedule
+	id       string
+}
+
+// Id returns the cron job id.
+func (j *Job) Id() string {
+	return j.id
+}
+
+// Expr returns the plain cron job schedule expression.
+func (j *Job) Expr() string {
+	return j.schedule.rawExpr
+}
+
+// Run runs the cron job function.
+func (j *Job) Run() {
+	if j.fn != nil {
+		j.fn()
+	}
+}