Reflect changes to StorageExtension in README.

Author: Benjamin Maurer

README.md

@@ -69,19 +69,21 @@ It is possible to manually clear the journal an snapshot storage, for example:
 
 ```scala
 import akka.actor.ActorSystem
-import akka.persistence.inmemory.extension.{ InMemoryJournalStorage, InMemorySnapshotStorage, StorageExtension }
+import akka.persistence.inmemory.extension.{ InMemoryJournalStorage, InMemorySnapshotStorage, StorageExtensionProvider }
 import akka.testkit.TestProbe
 import org.scalatest.{ BeforeAndAfterEach, Suite }
 
 trait InMemoryCleanup extends BeforeAndAfterEach { _: Suite =>
 
+  def config: Config
   implicit def system: ActorSystem
 
   override protected def beforeEach(): Unit = {
     val tp = TestProbe()
-    tp.send(StorageExtension(system).journalStorage, InMemoryJournalStorage.ClearJournal)
+    val extension = StorageExtensionProvider(system)
+    tp.send(extension.journalStorage(config), InMemoryJournalStorage.ClearJournal)
     tp.expectMsg(akka.actor.Status.Success(""))
-    tp.send(StorageExtension(system).snapshotStorage, InMemorySnapshotStorage.ClearSnapshots)
+    tp.send(extension.snapshotStorage(config), InMemorySnapshotStorage.ClearSnapshots)
     tp.expectMsg(akka.actor.Status.Success(""))
     super.beforeEach()
   }