Support Aftershow

In this pull req, I responded to an issue: https://github.com/rejasupotaro/Rebuild/issues/38. 

- [x] Catch the exception that occurred on parsing RSS item (err on the side of caution)
- [x] Restructure to the table schema that is according to a rule about the naming of RSS
- [x] Data migration
- [x] Version up test to confirm that the migration is working well