Update to Drupal 8.1.1. For more information, see https://www.drupal.org/node/2718713

core/modules/quickedit/tests/modules/quickedit_test.module

@@ -18,4 +18,3 @@ function quickedit_test_quickedit_render_field(EntityInterface $entity, $field_n
     '#suffix' => '</div>',
   );
 }
-

core/modules/quickedit/tests/src/Kernel/EditorSelectionTest.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace Drupal\quickedit\Tests;
+namespace Drupal\Tests\quickedit\Kernel;
 
 use Drupal\entity_test\Entity\EntityTest;
 use Drupal\quickedit\EditorSelector;

core/modules/quickedit/tests/src/Kernel/MetadataGeneratorTest.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace Drupal\quickedit\Tests;
+namespace Drupal\Tests\quickedit\Kernel;
 
 use Drupal\entity_test\Entity\EntityTest;
 use Drupal\quickedit\EditorSelector;

core/modules/quickedit/tests/src/Kernel/QuickEditTestBase.php

@@ -1,9 +1,9 @@
 <?php
 
-namespace Drupal\quickedit\Tests;
+namespace Drupal\Tests\quickedit\Kernel;
 
 use Drupal\field\Entity\FieldConfig;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\field\Entity\FieldStorageConfig;
 
 /**