add migration file

physionet-django/events/migrations/0007_event_event_agreement.py

@@ -0,0 +1,20 @@
+# Generated by Django 3.2.16 on 2023-02-28 20:41
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('events', '0006_eventagreement_eventagreementsignature'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='event',
+            name='event_agreement',
+            field=models.ForeignKey(null=True,
+                                    on_delete=django.db.models.deletion.SET_NULL, to='events.eventagreement'),
+        ),
+    ]