Add debate translations

db/migrate/20181130141019_add_debates_translations.rb

@@ -0,0 +1,15 @@
+class AddDebatesTranslations < ActiveRecord::Migration[4.2]
+  def self.up
+    Debate.create_translation_table!(
+      {
+        title:               :string,
+        description:         :text
+       },
+      { migrate_data: true }
+    )
+  end
+
+  def self.down
+    Debate.drop_translation_table!
+  end
+end