cli: rails g model Micropost content:string user_id:integer
*_create_microposts.rb: added multiple-key index
schema.rb: cli: rake db:migrate
micropost_spec.rb: tested for user creation of a micropost
micropost_spec.rb: added tests from Hartl listing 10.3
micropost.rb: added validation for :user_id presence
micropost_spec.rb: added tests from Hartl listing 10.5
user_spec.rb: added test from Hartl listing 10.6
micropost_spec.rb: set expression to var; added parentheses
user.rb, micropost.rb: added associations
factories.rb: added :micropost factory
user_spec.rb: added tests from Hartl listing 10.10
micropost.rb: added default_scope for 'created_at DESC'
user_spec.rb: fixed typo
user_spec.rb: added test from Hartl listing 10.12
user.rb: added 'dependent: :destroy' option to user association