Fixed and added test-case for next-tick events added by timers.
Fixed and added test-case for next-tick events added by timers.

steverhoades/event-loop,mkrauser/event-loop,mkrauser/event-loop,steverhoades/event-loop,kaduev13/event-loop,reactphp/event-loop,clue-labs/event-loop,kaduev13/event-loop