suppress series tags in meta for childrens books site

Apply the same meta logic as per comment is free to articles in the http://www.theguardian.com/childrens-books-site - don't show the series or blog tag,just a link to children's books: 

Before: 
![childrens-books-after](https://cloud.githubusercontent.com/assets/986155/5246812/c9ec88ac-7964-11e4-9cb4-08cccd7b5f8c.png)

After:
![children s-books-after](https://cloud.githubusercontent.com/assets/986155/5246819/db787d7e-7964-11e4-8279-e70af916b212.png)