Introduce yarn + webpack

[maoo]

Currently the packaging and deployment of all web assets are manually managed, which (as I'm sure you've experienced) makes code a lot less modular, and tougher to maintain.

It is highly suggested to use a tool like Webpack to take care of this for you. In this case, you would build your project using webpack, and then publish the generated files to your gh-pages branch. Webpack can bundle raw Javascript with jQuery like you have, or can work with a full SPA framework like Angular, React, etc. Here is a good example to do this using something like React. The addition of a build manager like Webpack will make your code significantly more modular and maintainable, since you can require(*) files in your written javascript, and then have webpack build the dependency tree into a single deployed javascript file.

yarn + webpack = super maintainable codebase

/CC @kbarresi @Kabrakssis

[jonfreedman]

Whether or not you use Yarn or just NPM when you make this change it would probably be worthwhile looking at TypeScript or Flow as part of the build step. You can then stick some unit tests in and start using the foundation recommended static analysis tools. Feel free to take some of the npm configuration from hubot-symphony.