Add migration to remove values from SiteConfiguration and unskip migration test.

common/djangoapps/util/tests/test_db.py

@@ -223,8 +223,7 @@ class MigrationTests(TestCase):
     """
 
     @unittest.skip(
-        "Need to skip as part of renaming a field in schedules app. This will be unskipped in DE-1825.  ALSO need to "
-        "skip as part of renaming a field in the site_configuration app.  This will be unskipped in DENG-18."
+        "Need to skip as part of renaming a field in schedules app. This will be unskipped in DE-1825."
     )
     @override_settings(MIGRATION_MODULES={})
     def test_migrations_are_in_sync(self):

openedx/core/djangoapps/site_configuration/migrations/0007_remove_values_field.py

@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('site_configuration', '0006_copy_values_to_site_values'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='siteconfiguration',
+            name='values',
+        ),
+        migrations.RemoveField(
+            model_name='siteconfigurationhistory',
+            name='values',
+        ),
+    ]