confirmation: Add a field `presume_email_valid` to RealmCreationKey.

confirmation/migrations/0006_realmcreationkey_presume_email_valid.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.6 on 2018-01-29 18:39
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('confirmation', '0005_confirmation_realm'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='realmcreationkey',
+            name='presume_email_valid',
+            field=models.BooleanField(default=False),
+        ),
+    ]

confirmation/models.py

@@ -151,3 +151,7 @@ def generate_realm_creation_url() -> Text:
 class RealmCreationKey(models.Model):
     creation_key = models.CharField('activation key', max_length=40)
     date_created = models.DateTimeField('created', default=timezone_now)
+
+    # True just if we should presume the email address the user enters
+    # is theirs, and skip sending mail to it to confirm that.
+    presume_email_valid = models.BooleanField(default=False)  # type: bool