add dependency to zmq lib

I needed to add this dep in order to resolve the following error :

```
Traceback (most recent call last):
  File "/domoweb/Domoweb.py", line 10, in <module>
    from zmq.eventloop import ioloop
ImportError: No module named zmq.eventloop
```
Merge pull request #10 from ka2er/patch-1

add dependency to zmq lib