Remove reference to deprecated Role class in tests

src/Bundle/ChillMainBundle/Test/Export/AbstractExportTest.php

@@ -18,12 +18,9 @@ use RuntimeException;
 use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
 use Symfony\Component\BrowserKit\HttpBrowser;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\Security\Core\Role\Role;
-use Traversable;
 
 use function call_user_func;
 use function count;
-use function is_array;
 use function is_callable;
 use function is_string;
 
@@ -370,12 +367,7 @@ abstract class AbstractExportTest extends WebTestCase
     {
         $role = $this->getExport()->requiredRole();
 
-        $this->assertInstanceOf(
-            Role::class,
-            $role,
-            sprintf('test that the returned value of `requiredRole` is an instance '
-            . 'of %s', Role::class)
-        );
+        self::assertIsString($role);
     }
 
     /**