Fix mcrouter/lib/fibers/FibersTest.cpp
Fix mcrouter/lib/fibers/FibersTest.cpp

Summary: Increse time intervals to make the test more stable

Test Plan: t

Reviewed By: pavlo@fb.com

FB internal diff: D1433591

easyfmxu/mcrouter,apinski-cavium/mcrouter,leitao/mcrouter,reddit/mcrouter,zhlong73/mcrouter,tempbottle/mcrouter,facebook/mcrouter,evertrue/mcrouter,is00hcw/mcrouter,yqzhang/mcrouter,nvaller/mcrouter,apinski-cavium/mcrouter,synecdoche/mcrouter,facebook/mcrouter,apinski-cavium/mcrouter,tempbottle/mcrouter,is00hcw/mcrouter,synecdoche/mcrouter,evertrue/mcrouter,easyfmxu/mcrouter,facebook/mcrouter,reddit/mcrouter,yqzhang/mcrouter,reddit/mcrouter,glensc/mcrouter,seem-sky/mcrouter,seem-sky/mcrouter,glensc/mcrouter,glensc/mcrouter,zhlong73/mcrouter,synecdoche/mcrouter,zhlong73/mcrouter,zhlong73/mcrouter,apinski-cavium/mcrouter,evertrue/mcrouter,leitao/mcrouter,nvaller/mcrouter,evertrue/mcrouter,tempbottle/mcrouter,leitao/mcrouter,nvaller/mcrouter,reddit/mcrouter,seem-sky/mcrouter,yqzhang/mcrouter,leitao/mcrouter,seem-sky/mcrouter,is00hcw/mcrouter,easyfmxu/mcrouter,glensc/mcrouter,is00hcw/mcrouter,easyfmxu/mcrouter,synecdoche/mcrouter,nvaller/mcrouter,yqzhang/mcrouter,facebook/mcrouter,tempbottle/mcrouter