Return master branch to dev version

Change-Id: I6a94877a61a0d6be6b3db14c0171c471ed01272c
diff --git a/VERSION b/VERSION
index ccbccc3..84e6d84 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.2.0
+2.2.1-dev