To fix create @webroot (#95)

https://github.com/Codeception/Codeception/issues/3706

config/test.php

@@ -14,6 +14,9 @@ return [
         'mailer' => [
             'useFileTransport' => true,
         ],
+        'assetManager' => [            
+            'basePath' => __DIR__ . '/../web/assets',
+        ],
         'urlManager' => [
             'showScriptName' => true,
         ],