fix: Test 코드 변경

tests/BasicTest.php

@@ -1,5 +1,8 @@
 <?php
-class BasicTest extends PHPUnit\Framework\TestCase{
+
+use \PHPUnit\Framework\TestCase;
+
+final class BasicTest extends TestCase{
     public function testHelloWorld(){
         $this->assertEquals(1+1, 2);
     }