Make it easier to maintain this repo

[SpaceK33z]

Currently this is a complete fork of create-react-app. I don't have the time / mood to cherry pick commits from upstream anymore, and also create-react-app (CRA) has fixed a lot of the (minor) issues I had.

I updated the README with all changes I made compared to CRA, which is still a lot. However it is probably possible to do this another way (not forking everything).

One option is React App Rewired, which makes it easy to customize create-react-app by adding a config file in your project. I don't want to repeat this file in every project though, so I'd need to research how to implement this in create-react-cy-app.

Another option is to start over from scratch, but this time only fork the react-scripts + babel preset part. A lot of the changes required in react-scripts can be done via environment variables now, so if we can separate these env variables we have to make minimal changes to the code so pulling from upstream would succeed most of the time.

[SpaceK33z]

Note that as a result of this, we'll get an even more awesome error overlay in the browser (since CRA improved it a lot meanwhile)

[SpaceK33z]

Allright let's do it.

• Update react-cy-scripts to latest master
• Fix eslint config for this repository
• Re-apply changes react-cy-scripts, but better if possible;
  • Try to use NODE_PATH env instead of custom hack for src/ module resolving
  • Try out eslint-loader, maybe we should use it after all
  • Disable source maps via env variable instead of hack
  • Remove css autoprefixer
  • Use cache-loader for babel
  • Support PUBLIC_URL env in dev
  • Use babel-minify
  • Add basic Electron compat
  • Add CY_ENV_FILE support
  • Change frontend env variable prefix to CY_FRONTEND_*
  • Update template to react-cy-scripts
• Publish 1.0.0 version
• Simplify README

Bonus points:

• Fix kitchensink tests
• Enable Travis again