Enable recursive upload/download of folders


```sh
$ git clone https://github.com/zachriggle/peda /tmp/peda
```

```python
from pwn import *
shell = ssh(host='bandit.labs.overthewire.org', user='bandit0', password='bandit0')
wd = shell.set_working_directory()
shell.upload_dir('/tmp/peda')
print shell['ls -la peda']
shell.download_dir('peda')
```

```
$ diff peda /tmp/peda
```