Add monitoring link with subtabs

app/views/admin/background_jobs/_head.html.haml

+%ul.nav-links.sub-nav
+  %div{ class: (container_class) }
+    = nav_link(controller: :background_jobs) do
+      = link_to admin_background_jobs_path, title: 'Background Jobs' do
+        %span
+          Background Jobs
+    = nav_link(controller: :logs) do
+      = link_to admin_logs_path, title: 'Logs' do
+        %span
+          Logs
+    = nav_link(controller: :health_check) do
+      = link_to admin_health_check_path, title: 'Health Check' do
+        %span
+          Health Check

app/views/admin/background_jobs/show.html.haml

+- @no_container = true
 - page_title "Background Jobs"
-%h3.page-title Background Jobs
-%p.light GitLab uses #{link_to "sidekiq", "http://sidekiq.org/"} library for async job processing
+= render 'admin/background_jobs/head'
 
-%hr
+%div{ class: (container_class) }
+  %h3.page-title Background Jobs
+  %p.light GitLab uses #{link_to "sidekiq", "http://sidekiq.org/"} library for async job processing
 
-.panel.panel-default
+  %hr
+
+  .panel.panel-default
     .panel-heading Sidekiq running processes
     .panel-body
       - if @sidekiq_processes.empty?
@@ -42,5 +46,5 @@
 
 
 
-.panel.panel-default
+  .panel.panel-default
     %iframe{src: sidekiq_path, width: '100%', height: 970, style: "border: none"}

app/views/admin/health_check/show.html.haml

+- @no_container = true
 - page_title "Health Check"
+= render 'admin/background_jobs/head'
 
-%h3.page-title
+%div{ class: (container_class) }
+  %h3.page-title
     Health Check
-.bs-callout.clearfix
+  .bs-callout.clearfix
     .pull-left
       %p
     Access token is
@@ -12,7 +15,7 @@
       data: { confirm: 'Are you sure you want to reset the health check token?' } do
       = icon('refresh')
       Reset health check access token
-%p.light
+  %p.light
     Health information can be retrieved as plain text, JSON, or XML using:
     %ul
       %li
@@ -22,7 +25,7 @@
       %li
         %code= health_check_url(token: current_application_settings.health_check_access_token, format: :xml)
 
-%p.light
+  %p.light
     You can also ask for the status of specific services:
     %ul
       %li
@@ -32,8 +35,8 @@
       %li
         %code= health_check_url(token: current_application_settings.health_check_access_token, checks: :migrations)
 
-%hr
-.panel.panel-default
+  %hr
+  .panel.panel-default
     .panel-heading
       Current Status:
       - if @errors.blank?

app/views/admin/logs/show.html.haml

+- @no_container = true
 - page_title "Logs"
 - loggers = [Gitlab::GitLogger, Gitlab::AppLogger,
              Gitlab::ProductionLogger, Gitlab::SidekiqLogger,
              Gitlab::RepositoryCheckLogger]
-%ul.nav-links.log-tabs
+= render 'admin/background_jobs/head'
+
+%div{ class: (container_class) }
+  %ul.nav-links.log-tabs
     - loggers.each do |klass|
       %li{ class: (klass == Gitlab::GitLogger ? 'active' : '') }
         = link_to klass::file_name, "##{klass::file_name_noext}",
             'data-toggle' => 'tab'
-.row-content-block
+  .row-content-block
     To prevent performance issues admin logs output the last 2000 lines
-.tab-content
+  .tab-content
     - loggers.each do |klass|
       .tab-pane{ class: (klass == Gitlab::GitLogger ? 'active' : ''),
           id: klass::file_name_noext }

app/views/layouts/nav/_admin.html.haml

@@ -16,14 +16,10 @@
     = link_to admin_builds_path, title: 'Builds' do
       %span
         Builds
-  = nav_link(controller: :logs) do
-    = link_to admin_logs_path, title: 'Logs' do
+  = nav_link(controller: %w(background_jobs logs health_check)) do
+    = link_to admin_background_jobs_path, title: 'Monitoring' do
       %span
-        Logs
-  = nav_link(controller: :health_check) do
-    = link_to admin_health_check_path, title: 'Health Check' do
-      %span
-        Health Check
+        Monitoring
   = nav_link(controller: :broadcast_messages) do
     = link_to admin_broadcast_messages_path, title: 'Messages' do
       %span
@@ -32,10 +28,7 @@
     = link_to admin_hooks_path, title: 'Hooks' do
       %span
         Hooks
-  = nav_link(controller: :background_jobs) do
-    = link_to admin_background_jobs_path, title: 'Background Jobs' do
-      %span
-        Background Jobs
+
   = nav_link(controller: :appearances) do
     = link_to admin_appearances_path, title: 'Appearances' do
       %span