Exec example for copying files to pod

Managed to download file from pod by creating a writestream and using it as stdout
```
const downloadCommand = ["tar", "czpf", "-", `${remotePath}`];
const localFile = fs.createWriteStream(localPath);
Exec.exec(nameSpace, podName, containerName, downloadCommand, localFile, null, null, false);
``` 

But I wouldn't know how to upload a file/folder to the container.

Anyone can help me out?