Release voltha-go 2.1 branch version 2.1.3

Change-Id: I0b6e57b52b081f7fcb566b57c0827b3ff46f53d2
diff --git a/VERSION b/VERSION
index 7783fad..ac2cdeb 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.1.3-dev
+2.1.3
diff --git a/python/adapters/ponsim_olt/VERSION b/python/adapters/ponsim_olt/VERSION
index 7f8d85c..ac2cdeb 100644
--- a/python/adapters/ponsim_olt/VERSION
+++ b/python/adapters/ponsim_olt/VERSION
@@ -1 +1 @@
-2.1.2-dev
+2.1.3
diff --git a/python/adapters/ponsim_onu/VERSION b/python/adapters/ponsim_onu/VERSION
index 7f8d85c..ac2cdeb 100644
--- a/python/adapters/ponsim_onu/VERSION
+++ b/python/adapters/ponsim_onu/VERSION
@@ -1 +1 @@
-2.1.2-dev
+2.1.3