Improve test coverage for API.

app/Services/Internal/Destroy/BillDestroyService.php

@@ -38,7 +38,7 @@ class BillDestroyService
      */
     public function __construct()
     {
-        if ('testing' === env('APP_ENV')) {
+        if ('testing' === config('app.env')) {
             Log::warning(sprintf('%s should not be instantiated in the TEST environment!', \get_class($this)));
         }
     }