[react-page-middleware] Stop crashing the server on syntax error.

Summary:As titled.

Test Plan:Caused syntax error and did not observe crash.
Merge pull request #8 from jordwalke/StopCrashingOnSyntaxError

[react-page-middleware] Stop crashing the server on syntax error.
Updating jstransforms to unbreak.
Safely reference getWindowSize
Merge pull request #9 from abhilashi/get_window_size_issue

Safely reference getWindowSize