Adding the User model with name and email fields. 

Commands : 

$ rails generate scaffold User name:string email:String

$ bundle exec rake db:migrate
Adding the Micropost Model with content and user_id fields. 

Commands : 

$ rails generate scaffold Micropost content:string user_id:integer

$ bundle exec rake db:migrate
Constraining microposts to 140 characters in length
Adding relation between user and microposts. A user can have many microposts. A micropost can belong to a single user.