Add websocket to show live logs

Created by: player1537

• Django Remote Submission version: 0.7.0
• Django version: n/a
• Python version: n/a
• Operating System: n/a

Description

Basically the same as #11 (closed) but there should be a websocket that shows the latest logs from the running tasks.

Like in #23, this should add a new post_save signal to signals.py that listens for each new Log object, and then writes to a Group('job-log-{}'.format(log.job.id)).

There will also need to be another example page to show how to use this websocket, but it will be about the same as the current one for job statuses.