Add art work and its url to DojoCast's feed

Author: yasulab

app/controllers/podcasts_controller.rb

@@ -19,6 +19,7 @@ def feed
     @episodes     = Podcast.all.sort_by{|episode| episode.published_at}
     @base_url     = request.base_url
     @author       = "一般社団法人 CoderDojo Japan"
+    @art_work_url = "https://coderdojo.jp/podcasts/cover.jpg"
     @current_year = Time.current.year
     respond_to do |format|
       format.rss { render :layout => false }

app/views/podcasts/feed.rss.builder

@@ -4,6 +4,7 @@ xml.rss :version => "2.0", "xmlns:itunes" => "http://www.itunes.com/dtds/Podcast
     xml.title       full_title ""
     xml.description full_description ""
     xml.link        root_url
+    xml.image       @art_work_url
     xml.author      @author
     xml.copyright   "Copyright © 2012-#{@current_year} #{@author}"
     xml.language    "ja"