improved final test output

test.go

@@ -71,7 +71,13 @@ func test(redirects []Redirect) error { //TBD: implement
 	}
 
 	wg.Wait()
-	fmt.Printf("\ndone tests.\n---------------------------------------------\nSummary:\n\n%s", summaryOutput)
+	fmt.Printf("\ndone tests.\n---------------------------------------------\n")
+
+	if len(summaryOutput) > 0 {
+		fmt.Printf("Summary:\n\n%s", summaryOutput)
+	} else {
+		fmt.Println("All redirect tests succeeded.")
+	}
 
 	return nil
 }