Extend controllers from application controller
Extend application controller from main app application controller

This allow us to use the main application helper in the engine
Load helpers from main application

With this we are able to use helpers that is on the main application.
It also allow us to render the application layout here in the engine.
Allow to use routes from the main application

We need this to be able to render the application layout, since it uses route
helper such root_url or root_path and it is on the main application.
Create confirmations controller
Add confirmations#new view
Set layout as false on accounts#new
Add link to bank account confirmation on user page
Add method to check bank account availability
Create form to enter the verification amount
Add markup for pending contributions on new confirmation page
Get pending contributions to be paid
Remove duplicated conditional
Add a double to a contribution in spec
Improve language on confirmations new
Require user to be logged in on confirmations#new #29
Improve message on account already confirmed