This commit is a rough port to Django 2.1, Python 3 and a Docker based local development setup. Tests fail/error but migrations and the web frontend are already runnable. Task queue functionality is untested and translations seem to have trouble.
- implement websites.models.Website - add migration - implement websites.views.AddWebsite - implement websites.forms.AddWebsiteForm - define URL pattern 'add_website' in websites.urls - register Website model in websites.admin - add templates websites/base.html and websites/website_create.html - add german translation for new strings - add website URLs to gnuviechadmin.urls - add websites to INSTALLED_APPS - add changelog entry
