Started port to Django 2.1, Python 3, Docker

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.

gnuviechadmin/contact_form/forms.py

@@ -7,9 +7,9 @@ from __future__ import absolute_import, unicode_literals
 from django import forms
 from django.conf import settings
 from django.core.mail import send_mail
-from django.core.urlresolvers import reverse
 from django.template import RequestContext
 from django.template import loader
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
 
 from django.contrib.sites.models import Site

gnuviechadmin/contact_form/views.py

@@ -5,7 +5,7 @@ This module defines the views of the contact_form app.
 from __future__ import absolute_import, unicode_literals
 
 from django.shortcuts import redirect
-from django.core.urlresolvers import reverse_lazy
+from django.urls import reverse_lazy
 from django.views.generic import (
     FormView,
     TemplateView,
@@ -31,7 +31,7 @@ class ContactFormView(FormView):
     def get_initial(self):
         initial = super(ContactFormView, self).get_initial()
         currentuser = self.request.user
-        if currentuser.is_authenticated():
+        if currentuser.is_authenticated:
             initial['name'] = (
                 currentuser.get_full_name() or currentuser.username)
             initial['email'] = currentuser.email