Actually link to the advertised file

Was linking to http://content.guardianapis.com/search?q=debate&tag=politics/politics&from-date=2014-01-01 when the link label was actually http://content.guardianapis.com/search?q=debate&tag=tone/news,politics/politics&from-date=2014-01-01
Merge pull request #5 from kaelig/patch-1

Actually link to the advertised file