VOL-5139 - Create beta-release branch for voltha-onos

VERSION
-------
  o Bump string to the next *-dev version to avoid future conflicts with
    the v2.12 release branch.

Change-Id: I69041898353653df05c432306917c157f46b2798
diff --git a/VERSION b/VERSION
index b21411a..24fadfe 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-5.1.5-dev
+5.1.6-dev