Bump version to -dev

Change-Id: I0e4c20481ec001445df6aaff24acd0088a350bb1
diff --git a/VERSION b/VERSION
index 530cdd9..7c8d436 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.2.4
+2.2.5-dev