DAT-2380 Remove Holmes i.e. ArticleType  to reduce timeouts on indexer

this PR is mirrored #5828 

This change is only backend change that removes indexing of article_type through our old process.
The new indexing pipeline is handling that right now. 
Currently indexing article type causes spontaneous timeouts when asking service for article type.
https://github.com/Wikia/holmes_2/blob/master/src/main/java/artclassifier/RabbitHole.java#L145