Susceptible to changing NODE_ENV

[ssorallen]

Because this currently loads the development version of React, the outcomes of its NODE_ENV === 'production' checks will change based on the changing value of NODE_ENV.

Atom 1.8 updates Atom's ENV on new invocations from the command line, which often means NODE_ENV will change values on subsequent invocations. Changing from Atom's default NODE_ENV === production to the common case of an undefined NODE_ENV in users' shell environment can lead to crashes like was reported in Nuclide: facebookarchive/nuclide#463