added old rails manifest.json support
added old rails manifest.json support

shakacode/react_on_rails,shakacode/react_on_rails,shakacode/react_on_rails,shakacode/react_on_rails,szyablitsky/react_on_rails,szyablitsky/react_on_rails,szyablitsky/react_on_rails,shakacode/react_on_rails,szyablitsky/react_on_rails