http://ruby.railstutorial.org/chapters/a-demo-app

rails new demo_app --skip-bundle

cd demo_app
subl Gemfile
bundle install --without production

subl .gitignore

mv README.rdoc README.md
subl README.md

git init
git add .
git commit -m "Initial commit"

git remote add origin git@github.com/kaiwangchen/demo_app.git
git push -u origin master

rails generate scaffold User name:string email:string
bundle exec rake db:migrate

rails server  # http://localhost:3000/users

rails generate scaffold Micropost content:string user_id:integer
bundle exec rake db:migrate

rails server  # http://localhost:3000/microposts

# http://ruby.railstutorial.org/chapters/a-demo-app#sec-mvc_in_action
# rails console

rake assets:precompile