- added the gem Clearance for the authentication;
- created migration to create users table and generated the respective model;
- added a section to the application layout, for the session info and links;
- created the welcome controller and index view for the controller;
- added "welcome#index" to root path;
- added middlware for Clearance Backdoor;
- created test for sign_in;
- changed user's email of test;
- Fixed warnings made bu Hound;
- Fixed Indentation warning from Hound;
- Fixed indentation in WelcomeController;
- put the yield of the application layout in the right place;
Merge pull request #1 from cs-webdev/clearance_installation

Clearance installation
Adição do script de criação das tabelas referentes aos notebooks. Adição da listagem e criação de notebooks.
Added methods for searching and creating Notebooks.
Notebooks CRUD completed.
Fixed formatting errors reported by hound.
Removidos conflitos no routes.rb
Fixed small issues reported by zamith
Resolvido pequeno problema com o teste de listagem de Notebooks
Resolvidos conflitos restantes.