VOL-2828 Bump version for 2.3 release

Change-Id: If7e3fa4a3239c635c4a3761377a1928ff69f96b2
diff --git a/VERSION b/VERSION
index f70451d..cc6c9a4 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.3.5-dev
+2.3.5