Introducing Bootstrap 4

Bootstrap (and its dependency popper.js) are now used from npm packages,
allowing better version control and custom building of only the required
components for both styling and javascript.

At this moment the whole styling of bootstrap is included, once the Cloud
redesign is over it will be stripped to only the used components.

.gitignore

@@ -6,6 +6,7 @@ __pycache__
 
 /cloud/templates/
 /cloud/static/assets/css/
+/cloud/static/assets/js/bootstrap.min.js
 node_modules/
 
 /config_local.py