Update to Drupal 8.0.0. For more information, see https://www.drupal.org/node/2619030

core/modules/views/tests/fixtures/update/duplicate-field-handler.php

@@ -0,0 +1,11 @@
+<?php
+
+$connection = Drupal\Core\Database\Database::getConnection();
+
+$connection->insert('config')
+  ->fields(array(
+    'collection' => '',
+    'name' => 'views.view.test_duplicate_field_handlers',
+    'data' => serialize(\Drupal\Component\Serialization\Yaml::decode(file_get_contents('core/modules/views/tests/modules/views_test_config/test_views/views.view.test_duplicate_field_handlers.yml'))),
+  ))
+  ->execute();