Reworked imports in apps.articles.test_articles.test_models and created apps.articles.test_articles.test_views
Reworked urlpatterns names in articles.urls so that they are consistent and more intuitive based off of the view they use.  Created first unittest for views: ArticleDetailView
Added test for AuthorDetailView
Added test for TagDetailView.  Checks to make sure that view returns proper amount of articles that are associated with tag