VOL-2030 master branch voltha-openonu-adapter version 2.2.0

Change-Id: I1c9caf842f7861d64161917d833d05e614d06abc
diff --git a/VERSION b/VERSION
index 97ade15..ccbccc3 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.2.0-dev
+2.2.0