add services && controller && first configuration tree builder

BillingBundle/DependencyInjection/BillingExtension.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Bluesquare\BillingBundle\DependencyInjection;
+
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Extension\Extension;
+
+class BillingExtension extends Extension
+{
+    public function load(array $configs, ContainerBuilder $container)
+    {
+        $configuration = new Configuration();
+
+        $loader = new YamlFileLoader(
+            $container,
+            new FileLocator(__DIR__.'/../Resources/config')
+        );
+        $loader->load('services.yaml');
+
+        $this->addAnnotatedClassesToCompile([
+            'Bluesquare\\BillingBundle\\Controller\\'
+        ]);
+
+        $config = $this->processConfiguration($configuration, $configs);
+    }
+}