Add survey replies.

db/migrate/20160630094850_create_survey_replies.rb

@@ -0,0 +1,11 @@
+class CreateSurveyReplies < ActiveRecord::Migration
+  def change
+    create_table :survey_replies do |t|
+      t.integer :survey_question_id
+      t.integer :user_id
+      t.text :text
+
+      t.timestamps null: false
+    end
+  end
+end