Two more migrations for RAVEN

For some reason, django makemigration wasn't recognizing that the
voevent ivorn table actually existed, so it was trying to recreate
that table and the pytests were running into an issue.

gracedb/events/migrations/0042_auto_20191119_1730.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.23 on 2019-11-19 17:30
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('events', '0041_add_raven_voevent_fields'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='voevent',
+            name='ivorn',
+            field=models.CharField(blank=True, default='', editable=False, max_length=300),
+        ),
+    ]

gracedb/superevents/migrations/0006_add_raven_voevent_sevent_fields.py

 # -*- coding: utf-8 -*-
-# Generated by Django 1.11.23 on 2019-11-12 21:18
+# Generated by Django 1.11.23 on 2019-11-19 17:39
 from __future__ import unicode_literals
 
 import django.core.validators
@@ -63,7 +63,7 @@ class Migration(migrations.Migration):
             name='time_coinc_far',
             field=models.FloatField(blank=True, default=None, null=True, validators=[django.core.validators.MinValueValidator(0.0)]),
         ),
-        migrations.AddField(
+        migrations.AlterField(
             model_name='voevent',
             name='ivorn',
             field=models.CharField(blank=True, default='', editable=False, max_length=300),