Put wiki page history content into container

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

app/views/projects/wikis/history.html.haml

 - page_title "History", @page.title.capitalize, "Wiki"
 = render 'nav'
-
-.top-area
+%div{ class: (container_class) }
+  .top-area
     .nav-text
       %strong
         = link_to @page.title.capitalize, namespace_project_wiki_path(@project.namespace, @project, @page)
@@ -9,7 +9,7 @@
         ·
         History
 
-.table-holder
+  .table-holder
     %table.table
       %thead
         %tr