Updates dashboard poster controller

app/controllers/dashboard/poster_controller.rb

@@ -5,7 +5,10 @@ class Dashboard::PosterController < Dashboard::BaseController
     respond_to do |format|
       format.html
       format.pdf do
-        render pdf: 'poster', page_size: 'A3', show_as_html: Rails.env.test?
+        render pdf: 'poster',
+               page_size: 'A4',
+               show_as_html: Rails.env.test? || params.key?('debug'),
+               margin:  { top: 0 }
       end
     end
   end