MAGETWO-87698: Fix strict types.

Author: Eric Bohanon

dev/tests/integration/testsuite/Magento/Framework/GraphQl/Config/GraphQlReaderTest.php

@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\GraphQl\Config;
 
 use Magento\Framework\App\Cache;

dev/tests/integration/testsuite/Magento/Framework/GraphQl/_files/schema_response_sdl_description.php

@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 return [
     [
         'kind' =>  'OBJECT',

lib/internal/Magento/Framework/GraphQl/Query/Resolver/Argument/FieldEntityAttributesInterface.php

@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\GraphQl\Query\Resolver\Argument;
 
 /**

lib/internal/Magento/Framework/GraphQl/Query/Resolver/ContextInterface.php

@@ -3,6 +3,7 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\GraphQl\Query\Resolver;
 

lib/internal/Magento/Framework/GraphQl/Query/Resolver/Value.php

@@ -3,6 +3,7 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\GraphQl\Query\Resolver;
 

lib/internal/Magento/Framework/GraphQl/Query/Resolver/ValueFactory.php

@@ -3,6 +3,7 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\GraphQl\Query\Resolver;
 

lib/internal/Magento/Framework/GraphQlSchemaStitching/GraphQlReader/TypeMetaReaderInterface.php

@@ -3,6 +3,7 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\GraphQlSchemaStitching\GraphQlReader;