record the virtualenv used when a job or inventory sync runs

see: https://github.com/ansible/awx/issues/2264

awx/main/migrations/0056_v350_custom_venv_history.py

@@ -0,0 +1,25 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.16 on 2019-01-22 22:20
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('main', '0055_v340_add_grafana_notification'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='inventoryupdate',
+            name='custom_virtualenv',
+            field=models.CharField(blank=True, default=None, help_text='Local absolute file path containing a custom Python virtualenv to use', max_length=100, null=True),
+        ),
+        migrations.AddField(
+            model_name='job',
+            name='custom_virtualenv',
+            field=models.CharField(blank=True, default=None, help_text='Local absolute file path containing a custom Python virtualenv to use', max_length=100, null=True),
+        ),
+    ]