Update to webpack v3

[chocoelho]

It was announced that Webpack 3 was released[1]. We are currently supporting v2.2.1 according to our package.json file[2]. Webpack 3 is already stable, so we need to check if upgrading is possible now and if not we need to track what other necessary steps are required to update this package.

[1] https://medium.com/webpack/webpack-3-official-release-15fd2dd8f07b
[2]

django-react-boilerplate/package.json

Line 42 in 269bc46

"webpack": "^2.2.1",

[aericson]

Blocked by:
webpack/webpack-dev-server#946
webpack-contrib/extract-text-webpack-plugin#540

[chocoelho]

@aericson both PRs are now merged 😄