We want to seperate the creation of the tags from the crawler.
The creation of the tags requirements are as follow:

1. Cron job that runs every 24 hours.
2. Re-compute the tags of a plan if the last update time of the plan is after the last update time of the tags of this plan.
3. Before re-computing the tags of a plan, remove all previous tags for this plan.
4. The creation of father tags are not needed as of now, but beware that we need to add that functionality later. (Make sure that it will be comfortable to add this functionality)
5. This code should sit in the cron directory. It should resemble the existing crons in its behavior.