arduino#1456 - Avoid using hardcoded extension (address comment).

Author: 4ntoine

Diff for: commands/sketch/new.go

@@ -21,8 +21,9 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/arduino/arduino-cli/arduino/globals"	
 	"github.com/arduino/arduino-cli/commands"
-	"github.com/arduino/arduino-cli/configuration"
+	"github.com/arduino/arduino-cli/configuration"	
 	rpc "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/commands/v1"
 )
 
@@ -40,7 +41,7 @@ func CreateSketch(sketchDir string, sketchName string) (string, error) {
 		return "", err
 	}
 	baseSketchName := filepath.Base(sketchDir)
-	sketchFile := filepath.Join(sketchDir, baseSketchName+".ino")
+	sketchFile := filepath.Join(sketchDir, baseSketchName+globals.MainFileValidExtension)
 	if err := ioutil.WriteFile(sketchFile, emptySketch, os.FileMode(0644)); err != nil {
 		return "", err
 	}