Fixes #231

Implements a poster feature for the proposals dashboard

app/controllers/dashboard/poster_controller.rb

@@ -0,0 +1,16 @@
+class Dashboard::PosterController < Dashboard::BaseController
+  def index
+    authorize! :manage_poster, proposal
+
+    respond_to do |format|
+      format.html
+      format.pdf do
+        render pdf: 'poster', page_size: 'A3'
+      end
+    end
+  end
+
+  def new
+    authorize! :manage_poster, proposal
+  end
+end