Added flattr to the feed

[klaustopher]

This adds flattr to the feed ... The necessary infos for the auto URL stuff need to be added to the podcast.yml

---
flattr:
  user_id: klaustopher
  language: de_DE
  tags:
    - podcast
    - nerdkunde
    - technology
    # See https://api.flattr.com/rest/v2/categories.txt
  category: audio

Still to do

• Add tests for the Auto-Submit-URL generation to Podcast and Episode
• Refactor the duplication into a flattr helper class
• Fix Podcast#deep_link_url since it only handles GST-Kitchen URLs (@tisba, please let's talk about this)

[tisba]

Cool thing! I'll think about what we can do to make Podcast#deep_link_url customizable.

[tisba]

If I see this correctly, this is almost the same as in Podcast#flattr_auto_submit_link. Maybe we can factor this out into a helper, or something. I'm thinking about including ActiveSupport to get Hash#to_param to make this readable.

[klaustopher]

Well, it's a string with 7 params... So tje duplication isn't hurting so much in my eyes. But moving this out to a new class is fine with me as well... I can extract this out tomorrow when I add the tests

[klaustopher]

I removed the duplication and added the tests ... Any ideas about the deep link thingy? I have fixed it in my fork for our urls but I think forking the kitchen is not the way to go

[klaustopher]

Just noticed... We can remove the sanitize gem... I'll do that later