chore: update phpstan config

kenjis · kenjis · commit 248b2e9dd5d2 · 2021-02-01T14:21:41.000+09:00
diff --git a/phpstan.neon b/phpstan.neon
@@ -1,5 +1,5 @@
 parameters:
-  level: max
+  level: 6
   paths:
     - src
     - tests
