Fix IntegrityError deleting job splitting JT

misc:
*show sharded jobs in recent_jobs
*test updates

awx/main/migrations/0050_v340_unified_jt_set_null.py

@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.11 on 2018-09-10 17:41
+from __future__ import unicode_literals
+
+import awx.main.utils.polymorphic
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('main', '0049_v340_add_job_template'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='unifiedjob',
+            name='unified_job_template',
+            field=models.ForeignKey(default=None, editable=False, null=True, on_delete=awx.main.utils.polymorphic.SET_NULL, related_name='unifiedjob_unified_jobs', to='main.UnifiedJobTemplate'),
+        ),
+    ]