Renamed migrations to be a little more descriptive

Mainly for sanity when merging migrations into long running branches..
but nice anyways I think

awx/main/migrations/0005_v300_migrate_facts.py

@@ -0,0 +1,15 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from awx.main.migrations import _system_tracking as system_tracking
+from django.db import migrations
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('main', '0004_v300_fact_changes'),
+    ]
+
+    operations = [
+        migrations.RunPython(system_tracking.migrate_facts),
+    ]