Merge branch 'list-items' into 'master'

Remove div between ul and li

## What does this MR do?
Adds `container_class`to `ul` instead of `div` for valid HTML

## What are the relevant issue numbers?
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4592#note_12420843



See merge request !4633

app/assets/stylesheets/framework/nav.scss

@@ -74,6 +74,7 @@
 
     .container-fluid {
       background-color: $background-color;
+      margin-bottom: 0;
     }
 
     li {

app/views/projects/commits/_head.html.haml

 .scrolling-tabs-container
-  %ul.nav-links.sub-nav.scrolling-tabs
-    %div{ class: (container_class) }
+  .nav-links.sub-nav.scrolling-tabs
+    %ul{ class: (container_class) }
       .fade-left
       = nav_link(controller: %w(tree blob blame edit_tree new_tree find_file)) do
         = link_to project_files_path(@project) do

app/views/projects/issues/_head.html.haml

-%ul.nav-links.sub-nav
-  %div{ class: (container_class) }
+.nav-links.sub-nav
+  %ul{ class: (container_class) }
     - if project_nav_tab?(:issues) && !current_controller?(:merge_requests)
       = nav_link(controller: :issues) do
         = link_to url_for_project_issues(@project, only_path: true), title: 'Issues' do

app/views/projects/pipelines/_head.html.haml

-%ul.nav-links.sub-nav
-  %div{ class: (container_class) }
+.nav-links.sub-nav
+  %ul{ class: (container_class) }
     - if project_nav_tab? :pipelines
       = nav_link(controller: :pipelines) do
         = link_to project_pipelines_path(@project), title: 'Pipelines', class: 'shortcuts-pipelines' do