bug #667 Updated the kernel to the latest Symfony Flex recipe changes (javiereguiluz)

This PR was merged into the master branch.

Discussion
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Updated the kernel to the latest Symfony Flex recipe changes

This fixes #635 and updates the kernel according to https://github.com/symfony/recipes/blob/master/symfony/framework-bundle/3.3/src/Kernel.php

Commits
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0b833e3 Updated the kernel to the latest Symfony Flex recipe changes

Author: javiereguiluz

src/Kernel.php

@@ -18,10 +18,7 @@
 use Symfony\Component\HttpKernel\Kernel as BaseKernel;
 use Symfony\Component\Routing\RouteCollectionBuilder;
 
-/**
- * @author Fabien Potencier <fabien@symfony.com>
- */
-final class Kernel extends BaseKernel
+class Kernel extends BaseKernel
 {
     use MicroKernelTrait;
 
@@ -55,7 +52,7 @@ public function getLogDir(): string
         return dirname(__DIR__).'/var/log';
     }
 
-    public function registerBundles(): iterable
+    public function registerBundles()
     {
         $contents = require dirname(__DIR__).'/config/bundles.php';
         foreach ($contents as $class => $envs) {
@@ -65,17 +62,18 @@ public function registerBundles(): iterable
         }
     }
 
-    protected function configureContainer(ContainerBuilder $container, LoaderInterface $loader): void
+    protected function configureContainer(ContainerBuilder $container, LoaderInterface $loader)
     {
         $confDir = dirname(__DIR__).'/config';
         $loader->load($confDir.'/packages/*'.self::CONFIG_EXTS, 'glob');
         if (is_dir($confDir.'/packages/'.$this->environment)) {
             $loader->load($confDir.'/packages/'.$this->environment.'/**/*'.self::CONFIG_EXTS, 'glob');
         }
         $loader->load($confDir.'/services'.self::CONFIG_EXTS, 'glob');
+        $loader->load($confDir.'/services_'.$this->environment.self::CONFIG_EXTS, 'glob');
     }
 
-    protected function configureRoutes(RouteCollectionBuilder $routes): void
+    protected function configureRoutes(RouteCollectionBuilder $routes)
     {
         $confDir = dirname(__DIR__).'/config';
         if (is_dir($confDir.'/routes/')) {