- Change the `rmcmd` and `mkdircmd` functions to accept an OS parameter
- Remove `command_windows.go` file
- Modify `removeDestFile` and `Exec` functions to use the OS parameter
- Add OS detection logic to `removeAllDestFile` and `Exec` functions
- Modify `TestRemoveDestFile` function to use the OS parameter
fix https://github.com/appleboy/drone-scp/pull/119