Fixes #13882

* Update react-* to v16.7.0

* Upgrade react-hotkeys to v1.1.4

* Update react-intl to v2.7.2

* Update react-select to v2.2.0

* Update react-swipeable-views to v0.13.0

* Upgrade react-textarea-autosize to v7.1.0

* Upgrade redux to v4.0.1

* Upgrade reselect to v4.0.0

* Update raf to v3.4.1

* Update enzyme to v3.8.0

* Update rails-ujs to v5.2.2

* Update axios to v0.18.0

* Update http-link-header to v1.0.2

* Update rellax to v1.7.1

* Update intersection-observer to v0.5.1

* Update stringz to v1.0.0

* Upgrade babel-eslint to v10.0.1

* Update @babel/* to v7.2.x

* Update babel-plugin-react-intl to v3.0.1

* Update babel-plugin-transform-react-remove-prop-types to v0.4.21

* Upgrade dotenv to v6.2.0

* Update express to v4.16.4

* Update webpack to v4.28.3

* Upgrade autoprefixer to v9.4.3

* Update babel-loader to v8.0.4

* Upgrade css-loader to v2.1.0

* Upgrade file-loader to v3.0.1

* Update marky to v1.2.1

* Update mini-css-extract-plugin to v0.5.0

* Update offline-plugin to v5.0.6

* Update style-loader to v0.23.1

* Update eslint-plugin-jsx-a11y to v6.1.2

* yarn upgrade

* fix

* Replace webpack-manifest-plugin to webpack-assets-manifest

* Replace node-zopfli to @gfz/zopfli

* Remove monkey-patch for http-link-header

* Prepare to load onboarding as a full page

* Update the first-time introduction

* Improve responsive design

* Replace speech bubble with logo

* Increase text size and reword first paragraph