updated: Adapt to the new version of PHPUnit

Author: hong

.gitignore

@@ -1,3 +1,4 @@
 /vendor
 /composer.lock
 /.idea
+/.phpunit.result.cache

tests/PaginatorTest.php

@@ -10,7 +10,7 @@ class PaginatorTest extends TestCase
 {
     protected $maxId = 19;
 
-    protected function setUp()
+    protected function setUp(): void
     {
         parent::setUp();
 

tests/TestCase.php

@@ -10,7 +10,7 @@
 
 class TestCase extends BaseTestCase
 {
-    protected function setUp()
+    protected function setUp(): void
     {
         $app = new Application();
 
@@ -41,7 +41,7 @@ protected function setUp()
         });
     }
 
-    protected function tearDown()
+    protected function tearDown(): void
     {
         Manager::schema()->dropIfExists('posts');
         Manager::connection()->disconnect();