adds email sending preferences [#23]

db/migrate/20150806163142_add_preferences_to_users.rb

@@ -0,0 +1,6 @@
+class AddPreferencesToUsers < ActiveRecord::Migration
+  def change
+    add_column :users, :email_on_debate_comment, :boolean, default: false
+    add_column :users, :email_on_comment_reply, :boolean, default: false
+  end
+end