Update FileNameTest.php

tests/unit/Storage/Validator/FileNameTest.php

@@ -12,12 +12,12 @@ class FileNameTest extends TestCase
      */
     protected $object = null;
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->object = new FileName();
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
     }
 
@@ -30,4 +30,4 @@ class FileNameTest extends TestCase
         $this->assertEquals($this->object->isValid('test.png'), true);
         $this->assertEquals($this->object->isValid('test'), true);
     }
-}
+}