Deployment changes

These are a couple of changes that are needed to build and deploy the application to the test server. I will add the changes to the CI later. (That's why it's WIP.) Please check if those changes are good, because I have little idea what I'm doing! ;-)

Also, we should think about a way to change the URL in src/helpers.js. The CI needs to rewrite it, depending on which system to deploy to. Maybe a separate JS/config file to set those?