http://l4u.github.io/articles/create-a-rails-4-site-with-contact-us-form/

gistfile1.rb

# Example Gemfile for 
# http://l4u.github.io/articles/create-a-rails-4-site-with-contact-us-form/
# vim:fdm=marker fmr={,}
source 'https://rubygems.org'
ruby '2.0.0'

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.0.0'

# Use sqlite3 as the database for Active Record
gem 'sqlite3', group: [:development, :test]
gem 'pg', group: :production

# Use SCSS for stylesheets
gem 'sass-rails', '~> 4.0.0'

# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'

# Use CoffeeScript for .js.coffee assets and views
gem 'coffee-rails', '~> 4.0.0'

# See https://github.com/sstephenson/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby

# Use jquery as the JavaScript library
gem 'jquery-rails'

# Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
gem 'turbolinks'

# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 1.2'

group :doc do
  # bundle exec rake doc:rails generates the API under doc/api.
  gem 'sdoc', require: false
end

# Use ActiveModel has_secure_password
# gem 'bcrypt-ruby', '~> 3.0.0'

# Use unicorn as the app server
gem 'unicorn', group: :production

# Use Capistrano for deployment
# gem 'capistrano', group: :development

# Use debugger
# gem 'debugger', group: [:development, :test]

# Front-end {
gem 'bootstrap-sass', '~> 2.3.2.0'
gem 'haml-rails', '~> 0.4.0'
gem 'font-awesome-rails'
gem 'bootswatch-rails'
# }
# Forms, mail {
gem 'mail_form', '~> 1.5.0.rc'
gem 'simple_form', '~> 3.0.0.rc'
# }
# Development {
gem 'better_errors', group: :development
gem 'quiet_assets', group: :development
# }
# Development Guard {
gem 'guard-rails', group: :development
gem 'guard-livereload', group: :development
gem 'rack-livereload', group: :development
gem 'guard-bundler', group: :development
# }
# Server, heroku {
gem 'rails_12factor', group: :production
gem 'heroku-deflater', :group => :production
# }