Add fragment caching to player show page to artists panel and recent articles named with last_artist and number of artists for artist panel, and named by first podcast for recent podcasts, also add fragment caching for artists show page using artist and current user , furthermore add fragment caching to user page to subscription list and track list , using current user for subscription list and artist for track list. Finally add fragment cache for static parts as footer and jumbotron
solve issue of error raising when the user has not subscribed to any artists