Container does not need to inject an EmitterStack

- Since it's now the default behavior.

Author: weierophinney

src/Container/ApplicationFactory.php

@@ -133,7 +133,7 @@ public function __invoke(ContainerInterface $container)
 
         $emitter = $container->has(EmitterInterface::class)
             ? $container->get(EmitterInterface::class)
-            : $this->createEmitterStack();
+            : null;
 
         $app = new Application($router, $container, $finalHandler, $emitter);
 
@@ -175,18 +175,6 @@ private function injectRoutes(Application $app, ContainerInterface $container)
         }
     }
 
-    /**
-     * Create the default emitter stack.
-     *
-     * @return EmitterStack
-     */
-    private function createEmitterStack()
-    {
-        $emitter = new EmitterStack();
-        $emitter->push(new SapiEmitter());
-        return $emitter;
-    }
-
     /**
      * Given a collection of middleware specifications, pipe them to the application.
      *