version.py

Hi,
this is a small fix for the version.py file: when called as in python rq/version.py prints out the version string.
This is to work around the problem when redis (the python client) is not installed: 

```python
python -c 'import rq; print rq.__version__'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "rq/__init__.py", line 1, in <module>
    from .connections import get_current_connection
  File "rq/connections.py", line 2, in <module>
    from redis import StrictRedis
ImportError: No module named redis
```

Please ignore the .gitignore changes (I'm fairly new to github).