Update the latestReleaseBranch to release-1.3 in the munger.

cmd/mungedocs/mungedocs.go

@@ -30,7 +30,7 @@ import (
 )
 
 // This needs to be updated when we cut a new release series.
-const latestReleaseBranch = "release-1.2"
+const latestReleaseBranch = "release-1.3"
 
 var (
 	verbose   = flag.Bool("verbose", false, "On verification failure, emit pre-munge and post-munge versions.")

cmd/mungedocs/unversioned_warning_test.go

@@ -99,7 +99,7 @@ refer to the docs that go with that version.
 <!-- TAG RELEASE_LINK, added by the munger automatically -->
 <strong>
 The latest release of this document can be found
-[here](http://releases.k8s.io/release-1.2/filename.md).
+[here](http://releases.k8s.io/release-1.3/filename.md).
 
 Documentation for other releases can be found at
 [releases.k8s.io](http://releases.k8s.io).