add SignUp Confirmation (required by default, can be disabled in invitations) closes #6

passbook/core/migrations/0013_invitation_needs_confirmation.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.1.7 on 2019-02-25 19:57
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('passbook_core', '0012_nonce'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='invitation',
+            name='needs_confirmation',
+            field=models.BooleanField(default=True),
+        ),
+    ]