fix(changelog): raise no error when output is set to stdout and `CHAN…

…GELOG.md` does not exist

internal/cmd/release.go

@@ -76,7 +76,7 @@ func (c Command) runRelease(dst io.Writer, l *flash.Logger, cfg config.Changelog
 	title := fmt.Sprintf("%s (%s)", version, time.Now().Format(dateFormat))
 
 	old, err := ioutil.ReadFile(*c.file)
-	if err != nil {
+	if err != nil && !*c.toStdOut {
 		return err
 	}