Merge pull request #1317 from kaznovac/patch-1

PSR-14: PSR12 compliant code formatting

Author: mbniebergall

accepted/PSR-14-event-dispatcher.md

@@ -147,7 +147,7 @@ interface ListenerProviderInterface
      *   An iterable (array, iterator, or generator) of callables.  Each
      *   callable MUST be type-compatible with $event.
      */
-    public function getListenersForEvent(object $event) : iterable;
+    public function getListenersForEvent(object $event): iterable;
 }
 ```
 
@@ -173,6 +173,6 @@ interface StoppableEventInterface
      *   True if the Event is complete and no further listeners should be called.
      *   False to continue calling listeners.
      */
-    public function isPropagationStopped() : bool;
+    public function isPropagationStopped(): bool;
 }
 ```