"Fixes" for completing a build

- This will require a lot of unit testing to get right

InvenTree/stock/migrations/0032_stockitem_build_order.py

@@ -0,0 +1,20 @@
+# Generated by Django 3.0.5 on 2020-04-25 14:02
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('build', '0015_auto_20200425_1350'),
+        ('stock', '0031_auto_20200422_0209'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='stockitem',
+            name='build_order',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='stock_items', to='build.Build'),
+        ),
+    ]