Use better maintained go.bug.st/serial

This commit switches to serial port library to the better maintained
go.bug.st/serial library.

signer/main.go

@@ -4,41 +4,33 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"log"
 	"time"
 
+	log "github.com/sirupsen/logrus"
+	"go.bug.st/serial"
+
 	"git.cacert.org/cacert-gosigner/datastructures"
 	"git.cacert.org/cacert-gosigner/shared"
-
-	"github.com/goburrow/serial"
 )
 
 var (
 	address  string
 	baudrate int
-	databits int
-	stopbits int
-	parity   string
 )
 
 func main() {
 	flag.StringVar(&address, "a", "/dev/ttyUSB0", "address")
 	flag.IntVar(&baudrate, "b", 115200, "baud rate")
-	flag.IntVar(&databits, "d", 8, "data bits")
-	flag.IntVar(&stopbits, "s", 1, "stop bits")
-	flag.StringVar(&parity, "p", "N", "parity (N/E/O)")
 	flag.Parse()
 
-	config := serial.Config{
-		Address:  address,
+	serialMode := &serial.Mode{
 		BaudRate: baudrate,
-		DataBits: databits,
-		StopBits: stopbits,
-		Parity:   parity,
-		Timeout:  5 * time.Minute,
+		DataBits: 8,
+		StopBits: serial.OneStopBit,
+		Parity:   serial.NoParity,
 	}
-	log.Printf("connecting %+v", config)
-	port, err := serial.Open(&config)
+	log.Infof("connecting to %s using %+v", address, serialMode)
+	port, err := serial.Open(address, serialMode)
 	if err != nil {
 		log.Fatal(err)
 	}