MAGETWO-62807: Case information block on order details page in admin panel

- Fixed integration tests

Author: Dmytro Yushkin

Block/Adminhtml/CaseInfoTest.php

@@ -170,14 +170,13 @@ public function testButtonsForApprovedCase()
      */
     private function getBlockContents()
     {
+        $this->layout->addContainer('order_additional_info', 'Container');
+
         /** @var CaseInfo $block */
-        $block = $this->layout->createBlock(CaseInfo::class, 'order_case_info', ['context' => $this->getContext()]);
+        $block = $this->layout->addBlock(CaseInfo::class, 'order_case_info', 'order_additional_info');
+        $block->setAttribute('context', $this->getContext());
         $block->setTemplate('Magento_Signifyd::case_info.phtml');
 
-        /** @var Template $parent */
-        $parent = $this->layout->createBlock(Template::class, 'order_additional_info');
-        $parent->setChild('order_case_info', $block);
-
         return $block->toHtml();
     }