update spec for article model
update articles migration
update model associations
udpate specs for Topic
add topics migration
udpate topic specs
update topcis table with article_id
add Topic model
update models for topics association
update specs
update aritcle model
fix articles_controllers and views
update seed file
Merge pull request #38 from ospreys-2014/change_article_associations_xiran

Change article associations xiran