now can also read from stdin

cmd/go2junit/go2junit.go

@@ -68,9 +68,16 @@ func main() {
 		os.Exit(1)
 	}
 	filename := os.Args[1]
-
+	var file *os.File
-	file, _ := os.Open(filename)
+	if filename != "-" {
+		file, err := os.Open(filename)
+		if err != nil {
+			panic(err)
+		}
 		defer file.Close()
+	} else {
+		file = os.Stdin
+	}
 
 	scanner := bufio.NewScanner(file)
 	lineno := 0