making N non-editable for EMObservations

gracedb/events/migrations/0021_emobservation_N_not_editable.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.5 on 2018-04-30 17:56
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('events', '0020_tag_unique_name'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='emobservation',
+            name='N',
+            field=models.IntegerField(editable=False),
+        ),
+    ]

gracedb/events/models.py

@@ -386,7 +386,7 @@ class EMObservationBase(models.Model):
         abstract = True
         ordering = ['-created', '-N']
 
-    N = models.IntegerField(null=False)
+    N = models.IntegerField(null=False, editable=False)
     created = models.DateTimeField(auto_now_add=True)
     submitter  = models.ForeignKey(UserModel, null=False,
         related_name='%(app_label)s_%(class)s_set')

gracedb/superevents/migrations/0003_emobservation_N_not_editable.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.5 on 2018-04-30 17:56
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('superevents', '0002_superevent_label_unique_together'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='emobservation',
+            name='N',
+            field=models.IntegerField(editable=False),
+        ),
+    ]