Start version 2.2.6-dev0

Change-Id: Iaf8e303912a72729731a6f3f1e6d85c1786cb494
diff --git a/VERSION b/VERSION
index 21bb5e1..fb76694 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.2.5
+2.2.6-dev0