add creation timestamp to tracks

nonstop/migrations/0007_auto_20171003_1022.py

+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('nonstop', '0006_auto_20171002_2231'),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name='track',
+            options={'ordering': ['creation_timestamp']},
+        ),
+        migrations.AddField(
+            model_name='track',
+            name='creation_timestamp',
+            field=models.DateTimeField(auto_now_add=True, null=True),
+        ),
+    ]

nonstop/models.py

@@ -44,6 +44,11 @@ class Track(models.Model):
     cfwb = models.BooleanField('CFWB', default=False)
     nonstop_zones = models.ManyToManyField('emissions.Nonstop', blank=True)
 
+    creation_timestamp = models.DateTimeField(auto_now_add=True, null=True)
+
+    class Meta:
+        ordering = ['creation_timestamp']
+
     def get_absolute_url(self):
         return reverse('track-view', kwargs={'pk': self.id})