Integrate a scheduler service to perform automatic jobs at predifined times

[htmfilho]

Some operations should be automated to save user's time. For that, we need to integrate a scheduler to run code at a certain date and time.

[keniasousa]

The scheduler is similar to creating a recurrent event in a calendar, e.g. every last Friday of the month, every 15th of the month.

[htmfilho]

The goal here is just to integrate a scheduler in the application. The scheduler will be used to run the standing instructions as specified in #24. It is not business related.