Add monitoring for expired ignore rules.

golden/go/skiacorrectness/main.go

Index: golden/go/skiacorrectness/main.go
diff --git a/golden/go/skiacorrectness/main.go b/golden/go/skiacorrectness/main.go
index 86f06d3d59de5048f6f77d7ac985bdc3b530aae1..4278a52638f5992f315046cfab1d91b727d3253b 100644
--- a/golden/go/skiacorrectness/main.go
+++ b/golden/go/skiacorrectness/main.go
@@ -369,6 +369,10 @@ func main() {
 		NCommits:          *nCommits,
 	}
 
+	if err := ignore.Init(storages.IgnoreStore); err != nil {
+		glog.Fatalf("Failed to start monitoring for expired ignore rules: %s", err)
+	}
+
 	// Enable the experimental features.
 	if *startExperimental {
 		tallies, err = tally.New(storages)