Using methods repository_params and repositories.

Signed-off-by: Renan Fichberg <rfichberg@gmail.com>
Method persisted? generalized.

Signed-off-by: Renan Fichberg <rfichberg@gmail.com>
Revising repositories.

There's only the model left to revise.

Signed-off-by: Renan Fichberg <rfichberg@gmail.com>