Add deselected_source to Memberships

ynr/apps/popolo/migrations/0050_membership_deselected_source.py

@@ -0,0 +1,20 @@
+# Generated by Django 4.2.3 on 2023-09-21 16:33
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("popolo", "0049_membership_deselected"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="membership",
+            name="deselected_source",
+            field=models.URLField(
+                blank=True,
+                help_text="A URL to a source document about the deselection",
+            ),
+        ),
+    ]

ynr/apps/popolo/models.py

@@ -361,6 +361,11 @@ class Membership(Dateframeable, TimeStampedModel, models.Model):
         help_text="Whether this candidate was deselected by their party, but remains on the ballot",
     )
 
+    deselected_source = models.URLField(
+        blank=True,
+        help_text="A URL to a source document about the deselection",
+    )
+
     objects = MembershipQuerySet.as_manager()
 
     def save(self, *args, **kwargs):