SEBA-736 release kubernetes-service 1.3.1

Change-Id: I79e8346216c48be5694e778e61f188a816bc588d
diff --git a/VERSION b/VERSION
index 625610e..3a3cd8c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.3.1-dev
+1.3.1