Fetch fresh status value on every request.

It could probably require a bit of caching, to prevent too many fetches
per time slot (for example, return the locally cached value if that
value is as fresh as a second or so).

This fixes #120.

rq/job.py

@@ -89,6 +89,7 @@ class Job(object):
 
     @property
     def status(self):
+        self._status = self.connection.hget(self.key, 'status')
         return self._status
 
     @property