category and post_categories with label view on blog_posts#index
remove category.html.haml
create set_recent_posts and set_categories methods for sidebar instvars
refactor blog post type query to blog_post_type private method
add GET blog tests for @recent_posts and @categories
refactor sidebar and related tests for dry
Merge pull request #4 from leeduan/feature/post_categories

Feature/post categories