update tests

README.md

@@ -18,10 +18,12 @@ composer require superbalist/laravel-prometheus-exporter
 ```
 
 Register the service provider in app.php
+
+#### Laravel
 ```php
 'providers' => [
     // ...
-    Superbalist\LaravelPrometheusExporter\PrometheusServiceProvider::class,
+    Superbalist\LaravelPrometheusExporter\LaravelServiceProvider::class,
 ]
 ```
 
@@ -33,6 +35,11 @@ Register the facade in app.php
 ]
 ```
 
+#### Lumen
+```php
+$app->register(Superbalist\LaravelPrometheusExporter\LumenServiceProvider::class);
+```
+
 ## Configuration
 
 The package has a default configuration which uses the following environment variables.