Merge pull request #159 from udaysagar2177/fix2

add pre-shutdown action to be executed inside ChronicleHashCloseOnExitHook

src/main/java/net/openhft/chronicle/set/ChronicleSetBuilder.java

@@ -352,6 +352,11 @@ public final class ChronicleSetBuilder<K>
         return new SetFromMap<>((VanillaChronicleMap<K, DummyValue, ?>) map);
     }
 
+    @Override
+    public void setPreShutdownAction(Runnable preShutdownAction) {
+        chronicleMapBuilder.setPreShutdownAction(preShutdownAction);
+    }
+
     /**
      * @deprecated don't use private API in the client code
      */