[`Model::sync`](./trait.Model.html#method.sync) will synchronize your model's indexes with the database. It is an integral component of this system & allows you to delegate a majority of your database administration tasks to your services which are actually using the database.
This routine should be called once per model, early on at boottime. This routine will destroy
any indexes found on this model's collection which are not defined on this model (barring the
default index on `_id`).