optimize babel config
optimize babel config

blai/react-styleguide-app,edge/react-styleguide-generator,edge/react-styleguide-generator,subvisual/react-styleguide-generator,pocotan001/react-styleguide-generator,subvisual/react-styleguide-generator,pocotan001/react-styleguide-generator,blai/react-styleguide-app,theogravity/react-styleguide-generator-alt,theogravity/react-styleguide-generator-alt