Adding labels for first OPA test

Adding DQOK, PASTRO_READY, EMBRIGHT_READY, SKYMAP_READY,
GCN_PRELIM_SENT labels in advance of first OPA test.

gracedb/events/migrations/0024_add_labels.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.5 on 2018-06-28 10:40:45
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+# Create initial Label instances
+
+# List of label names, default colors, and descriptions
+LABELS = [
+    {
+        'name': 'SKYMAP_READY',
+        'defaultColor': 'green',
+        'description': 'Skymap is available.',
+    },
+    {
+        'name': 'EMBRIGHT_READY',
+        'defaultColor': 'green',
+        'description': 'EM Bright information is available.',
+    },
+    {
+        'name': 'PASTRO_READY',
+        'defaultColor': 'green',
+        'description': 'p_astro is available.',
+    },
+    {
+        'name': 'DQOK',
+        'defaultColor': 'green',
+        'description': 'Data quality information is available and does not veto the event.',
+    },
+    {
+        'name': 'GCN_PRELIM_SENT',
+        'defaultColor': 'black',
+        'description': 'A preliminary GCN has been sent.',
+    },
+]
+
+def add_labels(apps, schema_editor):
+    Label = apps.get_model('events', 'Label')
+
+    # Create labels
+    for label_dict in LABELS:
+        l, created = Label.objects.get_or_create(name=label_dict['name'])
+        l.defaultColor = label_dict['defaultColor']
+        l.description = label_dict['description']
+        l.save()
+
+def remove_labels(apps, schema_editor):
+    Label = apps.get_model('events', 'Label')
+
+    # Delete labels
+    for label_dict in LABELS:
+        try:
+            l = Label.objects.get(name=label_dict['name'])
+        except Label.DoesNotExist:
+            print('Label {0} not found to be deleted, skipping.' \
+                .format(label_dict['name']))
+            break
+        l.delete()
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('events', '0023_emobservation_fields_blank'),
+    ]
+
+    operations = [
+        migrations.RunPython(add_labels, remove_labels),
+    ]