Reading group entity.

Created model and its unit tests.

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

Signed-off-by: Fellipe Souto <fllsouto@gmail.com>
Signed-off-by: Renan Fichberg <rfichberg@gmail.com>
Reading group ownerships.

Signed-off-by: Fellipe Souto <fllsouto@gmail.com>
Signed-off-by: Renan Fichberg <rfichberg@gmail.com>
Creating reading group views.

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