Minor specs changes

spec/dummy/db/migrate/20180607053739_create_posts.rb

@@ -4,6 +4,7 @@ class CreatePosts < ActiveRecord::Migration[5.2]
   def change
     create_table :posts do |t|
       t.string :title
+      t.text :summary
       t.text :description
       t.belongs_to :author, foreign_key: true
       t.string :category