VOL-2828 Bump post-2.3 release

Change-Id: I24393d0783e5a9575ab63a5f147d5e061be9bd09
diff --git a/VERSION b/VERSION
index 91a5166..eef2640 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.3.26
+2.4.0-dev0