adds rake task for repocess file thumbnails [fixes SCI-831]

lib/tasks/paperclip.rake

@@ -22,10 +22,26 @@ namespace :paperclip do
     end
   end
 
-  desc "List all paperclip files"
+  desc 'List all paperclip files'
   task files: :environment do
     print_model_files Asset, :file
     print_model_files User, :avatar
   end
 
+  desc 'Reprocess the Assets attachents styles'
+  task reprocess: :environment do
+    error = false
+    Asset.find_each(batch_size: 100) do |asset|
+      next unless asset.is_image?
+      begin
+        asset.file.reprocess! :medium, :large
+      rescue
+        error = true
+        $stderr.puts "exception while processing #{asset.file_file_name} " \
+                     "ID: #{asset.id}:"
+      end
+    end
+    $stderr.puts 'All gone well! ' \
+                 'You can grab a beer now and enjoy the evening.' unless error
+  end
 end