- Upgrade dependencies
    - chai (3.5.0 -> 4.0.1)
    - chai-enzyme (0.6.1 -> 0.7.1)
    - sinon (2.2.0 -> 2.3.2)
- Change extensions from .jsx to .js
- Don't assign `React` to `global`
- Check code format using ESLint

* Update autoprefixer to version 7.1.0

* Update axios to version 0.16.1

* Update babel-cli to version 6.24.1

* Update babel-eslint to version 7.2.3

* Update babel-preset-react to version 6.24.1

* Update coffee-script to version 1.12.6

* Update css-loader to version 0.28.1

* Update express to version 4.15.2

* Update js-yaml to version 3.8.4

* Update mocha to version 3.4.1

* Update jsdom to version 10.1.0

* Update npmlog to version 4.1.0

* Update postcss-smart-import to version 0.7.0

* Update postcss-loader to version 2.0.5

* Update pg to version 6.1.5

* Update prop-types to version 15.5.10

* Update rails-ujs to version 5.1.1

* Update redis to version 2.7.1

* Update sass-loader to version 6.0.5

* Update stringz to version 0.2.0

* Update webpack to version 2.5.1

* Update style-loader to version 0.17.0

* Update sinon to version 2.2.0

* Update react-motion to version 0.5.0

* Update react-notification to version 6.7.0

* Update react-redux-loading-bar to version 2.9.0

* Update react-intl to version 2.3.0

* Update redux-immutable to version 4.0.0

* Update reselect to version 3.0.1

* Update react-toggle to version 3.0.1

* Update react-simple-dropdown to version 3.0.0

* Update react-router to version 3.0.5

* Update react-router-scroll to version 0.4.2

* Update react-toggle to version 4.0.1

* yarn upgrade