[Email Confirmable]

  - Add in .gitignore .rvmrc
  - Add email confirmable to devise
[Heroku Deployment]

  - Add config gmail
[Invite new user]

  - Add gem devise_invitable
  - Add send invitation
  - Devise invitable with strong parameters gem
[Agregar campo is_admin]

  - Si es admin puede ver el link Invite New User