Editors and authors can view unpublished posts
  in the blog (posts index)

Also, some improvement of layout and styling with bootstrap buttons
	modified:   app/controllers/posts_controller.rb
	modified:   app/policies/post_policy.rb
	modified:   app/views/posts/index.html.erb
	modified:   app/views/shared/_footer.html.erb
	modified:   app/views/shared/_nav.html.erb
	modified:   test/features/posts/visiting_post_list_test.rb
	modified:   test/fixtures/posts.yml
	modified:   test/fixtures/users.yml
	modified:   test/test_helper.rb