To use Bcrypt:
  uncomment "gem 'bcrypt', '~> 3.1.7'" in Gemfile
  User model should have password_digest attribute
  add "has_secure_password" to User
  add "validates_confirmation_of :password" to User (if you have password confirmation which you should!)

To display flash messages:
  add the following to views/layouts/application.html.erb right before yield line:
        <% flash.each do |key, value| %>
          <div class="alert -<%= key %>">
           <%= value %>
          </div>
        <% end  %>

To use RSpec with Capybara:
  add gem 'rspec-rails' and gem 'capybara' to Gemfile
  in rails_helper.rb: require 'capybara/rails' and add "config.include Capybara::DSL" to config block