Choosing metrics from a base tool

Signed off by: Diego Araújo <diegoamc90@gmail.com>
New metric configuration feature

Routes for choose_metric & new metric configuration
Missing acceptance tests

Signed off by: Renan Fichberg <rfichberg@gmail.com>
Refactored mezuro configuration

Renamed variables in view and controller.
Renamed the helper of mezuro configuration ownership.

signed-off-by: Fellipe Souto Sampaio <fllsouto@gmail.com>
Index metric configuration feature

signed-off-by: Guilherme Rojas V. de Lima <guilhermehrojas@gmail.com>