Merge branch 'proj-branches-index-scb' into 'master'

Resolve CE/EE diffs in project branches

See merge request gitlab-org/gitlab-ce!28261

app/views/projects/branches/index.html.haml

 - @no_container = true
 - page_title _('Branches')
+- add_to_breadcrumbs(_('Repository'), project_tree_path(@project))
 
 %div{ class: container_class }
   .top-area.adjust
@@ -44,6 +45,8 @@
         = link_to new_project_branch_path(@project), class: 'btn btn-success' do
           = s_('Branches|New branch')
 
+  = render_if_exists 'projects/commits/mirror_status'
+
   - if can?(current_user, :admin_project, @project)
     - project_settings_link = link_to s_('Branches|project settings'), project_protected_branches_path(@project)
     .row-content-block