10.1 Add the Micropost model
10.2 Add a validation of presence
10.1.3 belongs_to, has_many
10.1 order, dependent
10.1.5 Add validation of the Micropost
10.2 Display the microposts
10.2.2 Add a micropost sample data
10.3 Add the routing of Microposts
Forgot to add
10.3.1
10.3.2 Add the form of to create Micropost
10.3.3 Post a micropost
Add a feature to delete a Micropost
10.5.1 Add a spec of micropost count
10.5.3 Divide to two partials