VOL-2828 Bump post-2.3 release

Change-Id: Ie1023ca374efcdaba01d579d0ecb0ee3e7bac2d7
diff --git a/VERSION b/VERSION
index e75da3e..eef2640 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.3.6
+2.4.0-dev0