[Test] Improve testPauseResume_innerTask & testTry_cancel to reproduce chained-task-pause/resume bug & try() bug.
Fix 7464aca by not propagating pause/resume/cancel to upstream by default, but do so only in try() method instead (partially reverting #10 d489ef9)
Merge pull request #18 from ReactKit/no-cancelling-upstream

Don't propagate pause/resume/cancel to upstream.