Feature(deploy config) & tweaks

• Deployment is now fully automated with docker / docker-compose (Backend served through uWSGI with Nginx)
• Logs are configured in django and handled by a dedicated docker service (and kept for 30 days)
• Frontend crash logging handled through the backend
• Quick documentation of the deploy setup

Fixes #110 (closed) Fixes #66 (closed)

Also:

• Moved the envs directory to the more general server dir
• New Picture and File model/serializer/viewset added
• Image validator added (didn't use django image field as it wasn't supporting svg)
• Removed symbolink of assets from the frontend in the backend to make sure we can boot the server in no time