Too old job offers

[geoffroyw]

We have job offers that were posted in 2011. In my opinion, we should not display the one that are older than a year (or even less?).

[lporcheron]

The code is there (in ain7/tasks.py), but it was not called automatically...
I call this function manually tonight and celery will run this week in production (we need it for a couple of other background tasks).
It will hide all jobs offers older than 4 months.

[lporcheron]

Instead of having a task, I think we should filter offers not modified in the last 4 months. That make things much easier :)