Admin area using side nav

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/views/layouts/admin.html.haml

 !!! 5
 %html{ lang: "en"}
   = render "layouts/head", title: "Admin area"
-  %body{class: "#{app_theme} admin", :'data-page' => body_data_page}
+  %body{class: "#{app_theme} sidenav admin", :'data-page' => body_data_page}
     = render "layouts/broadcast"
     = render "layouts/head_panel", title: "Admin area"
-    %nav.main-nav.navbar-collapse.collapse
-      .container= render 'layouts/nav/admin'
-    .container
+    .page-with-sidebar
+      .sidebar-wrapper
+        = render 'layouts/nav/admin'
+      .content-wrapper
+        .container-fluid
           .content
             = render "layouts/flash"
+            .clearfix
               = yield
     = yield :embedded_scripts

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

-%ul
+%ul.nav-sidebar.navbar-collapse.collapse
   = nav_link(controller: :dashboard, html_options: {class: 'home'}) do
     = link_to admin_root_path, title: "Stats" do
       Overview