Bumps rq dependency from 0.3.0 to 0.3.3

The ColorizingStreamHandler referenced in the django_rq rqworker
command was created on 21-Aug-12, after 0.3.0, but was reverted on
30-Aug-12 (referencing issue #121) just prior to the release on 0.3.1.
It re-appeared on 2-Sep-12, was merged in just prior to the release
of 0.3.3. Basically, it appeared, then disappeared, then appeared
again, so if you installed from source you may well have seen it,
but can only be guaranteed from formal release 0.3.3 onwards.