Upgrade node-sass

[tjrexer]

Due to security issues, node-sass, webpack, & dependencies needs to be upgraded.

[Tobias112358]

I have a large-ish change that resolves this, migrates to newer dependencies, updates sass and removes gulp. If this is something you could be interested in let me know and I can set up a pull request.

Changes found here: https://github.com/Tobias112358/uc-react-notifications/tree/update/es6-module