Update to Jest 19

Created by: gaearon

Seems like a pretty sweet release: http://facebook.github.io/jest/blog/2017/02/21/jest-19-immersive-watch-mode-test-platform-improvements.html.

This is a breaking change so targeting 0.10. A PR to update is welcome. Also worth keeping an eye on https://github.com/facebook/jest/pull/2957.