Translate 2017-05-18-whats-new-in-create-react-app (#294)

* Translate 2017-05-18-whats-new-in-create-react-app

* Translate "webpack 2" section

* Translate "Runtime Error Overlay" section

* Translate "Progressive Web Apps by Default" section

* Translate "Jest 20" section

* Translate "Acknowledgements" section

* Translate "But Wait... There's More!" section

* Translate "Better Console Output" section

* Translate "Code Splitting with Dynamic import()" section

* Fixes from review