Minimal working version

* Upgrade dependencies
* Fix ugettext
* Fix bad urls

subscription/models.py

@@ -25,7 +25,7 @@
 from datetime import date, timedelta
 from django.db import models
 from django.utils import timezone
-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import gettext_lazy as _
 from django.conf import settings
 from django.core.exceptions import ValidationError
 from django.urls import reverse

subscription/views.py

@@ -23,7 +23,7 @@
 #
 
 from django.views.generic.edit import CreateView, FormView
-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import gettext_lazy as _
 from django.core.exceptions import PermissionDenied, ValidationError
 from django.urls import reverse_lazy
 from django import forms