Fix broken unittest

1) Control Flow should provide asyncIt helper for tests:
   ReferenceError: Fiber is not defined
    at Context.<anonymous> (/home/sulee/works/repos/synchronize/test/sync.js:132:12)
    at sync.fiber (/home/sulee/works/repos/synchronize/sync.js:133:12)
Add multiple arguments support defer type function

`defers` support multiple value return.
- normally call like `sync.defers()`, `sync.await` return array.
- pass strings like `sync.defers('a', 'b')`, `sync.await` return object.
Merge pull request #12 from d3m3vilurr/master

Add can receive multiple arguments defer function