Using ONOS 2.2.7 and releasing for VOLTHA 2.6

Change-Id: Ic702e9e561cacd8fe35a75f4653c128d1cfb1e9b
diff --git a/VERSION b/VERSION
index cf0f8bc..6aba2b2 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-4.2.0-dev12
+4.2.0