1.2.3 mkdir chapter01 && rails new first_app
1.2.4 Add group specification for sqlite3 gem (development group)
Improve the README file of first_app.
Merge branch 'modify-README' into chapter01_first_app
1.4 Add gem pg for production
Set config.serve_static_assets = false in production mode
Merge branch 'chapter01_first_app'