Platform refactor: Decoupling spotify, Adding scaffolding for youtube

[qzdl]

• Spotify removed from the core of the application
• notion of input / output platoform introduced
• enhancements to scraper:
  • youtube video id retrieved from breakdown page
• platform extension enabled from #9

[qzdl]

So it's looking much better all over the place; really wanting for some tests right now -- an awful, awful decision to go for classes