fix: use Scheduler.time.now() instead of time.Now()

[fufuok]

What does this do?

// Use my custom global time
scheduler.CustomTime(&my.GlobalTime{})

The actual execution time of the task will vary.

should use:

s.now().Unix() >= next.dateTime.Unix()

instead of:

time.Now().Unix() >= next.dateTime.Unix()

Which issue(s) does this PR fix/relate to?

List any changes that modify/break current functionality

Have you included tests for your changes?

Did you document any new/modified functionality?

• Updated example_test.go
• Updated README.md

Notes

[JohnRoesler]

thank you!

[fufuok]

#363