Summary: `yarn start` basically starves if watchman is still scanning the system, until that is completed (which took 40 minutes for me last time). Added a timeout of 1 minute, to signal that you can better to some dishes, instead of trying to hunt a bug that looks like an exception has been eaten somewhere (guess what I did..)
Reviewed By: timur-valiev
Differential Revision: D30806512
fbshipit-source-id: a2ebc3672d82f3388fc7b00f41c7e9c4f37794b3