Added tests for PHP 8.2.

Author: sunaoka

.github/workflows/test.yml

@@ -17,7 +17,7 @@ jobs:
         php-version: [
             '5.3', '5.4', '5.5', '5.6',
             '7.0', '7.1', '7.2', '7.3', '7.4',
-            '8.0', '8.1'
+            '8.0', '8.1', '8.2'
         ]
 
     steps: