Background task to refresh score data

[wgx731]

• Refresh API: refresh score data - loop all the current scores in the database to fetch new data from open DOTA API and update score data in the database)
• Clean Up API: clean up old score data - loop all the current scores in the database and remove the outdated data (e.g more than 1 week)
• A CRON kind of task to Refresh API
• A CRON kind of task to call Clean Up API