service: do not call osext if go1.8+ is used

pre_go1.8.go

@@ -0,0 +1,16 @@
+//+build !go1.8
+
+package service
+
+import (
+	"path/filepath"
+
+	"github.com/kardianos/osext"
+)
+
+func (c *Config) execPath() (string, error) {
+	if len(c.Executable) != 0 {
+		return filepath.Abs(c.Executable)
+	}
+	return osext.Executable()
+}

service.go

@@ -64,9 +64,6 @@ package service // import "github.com/kardianos/service"
 import (
 	"errors"
 	"fmt"
-	"path/filepath"
-
-	"github.com/kardianos/osext"
 )
 
 const (
@@ -117,13 +114,6 @@ type Config struct {
 	Option KeyValue
 }
 
-func (c *Config) execPath() (string, error) {
-	if len(c.Executable) != 0 {
-		return filepath.Abs(c.Executable)
-	}
-	return osext.Executable()
-}
-
 var (
 	system         System
 	systemRegistry []System

service_go1.8.go

@@ -0,0 +1,15 @@
+//+build go1.8
+
+package service
+
+import (
+	"os"
+	"path/filepath"
+)
+
+func (c *Config) execPath() (string, error) {
+	if len(c.Executable) != 0 {
+		return filepath.Abs(c.Executable)
+	}
+	return os.Executable()
+}