changed default sort direction

test/controllers/admin_controller_test.rb

@@ -9,4 +9,11 @@ class AdminControllerTest < ActionDispatch::IntegrationTest
     assert_redirected_to admin_login_path
     assert_match 'not authorized', flash[:error]
   end
+
+  test 'sort_column present' do
+    # a stupid coverage report thing.
+    admin_controller = AdminController.new
+
+    assert_equal :completed_at, admin_controller.send(:sort_column)
+  end
 end