Let's create an API endpoint to manage hearts for apps. - Authentication required. - /api/v2/heart/app/<slug> - POST to heart, DELETE to remove the heart - Should be behind the waffle switches created in bug 937246 and bug 937248 - There should also be an additional field on an authenticated response with a serialized apps indicating whether the authenticated user has hearted the app. We will need to extend both app_to_dict, es_app_to_dict, and the new AppSerializer that ashort is working on. - Documentation