Revert 5da0e135b6224a2ec9677da3494b8c1e90b06908

It caused problems on Windows unfortunately and when we tried to
fix it we got: https://github.com/facebook/react-native/issues/5159

Reverting to unblock people. In the future we'll do careful rc
releases of the CLI. We should try to make the change again without
breaking anyone, regardless of OS (OSX, Linux, Windows) or npm version.