init comments

db/migrate/20170210165110_create_quiz_comments.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+class CreateQuizComments < ActiveRecord::Migration[5.0]
+  def change
+    create_table :quiz_comments do |t|
+      t.integer :user_id
+      t.string :test_hash
+      t.text :message
+
+      t.timestamps
+    end
+  end
+end