Added november reminder email

Could do with a few :eyes: on this just to check I've not made any obvious typos or grammar mistakes. 

You can preview the HTML email when running the app locally at `http://localhost:3000/rails/mailers/reminder_mailer/november` using the new [mail preview](http://api.rubyonrails.org/v4.1.0/classes/ActionMailer/Base.html#class-ActionMailer::Base-label-Previewing+emails) feature in Rails 4.1