Proxy support is not working

Proxy support is not working because of a wrong import.

In https://github.com/CiscoUcs/imcsdk/blob/master/imcsdk/imcdriver.py:

```
from six.moves import urllib as urllib2
```

But urlib is used:

```
            proxy_handler = urllib.request.ProxyHandler(
```

If I fix the import, other errors happen.
