Merge branch 'improve-broadcast-messages' into 'master'

Improve admin broadcast messages page

* Show latest broadcast messages first on admin page
* Use nice looking pagination

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

Fixes #13211 

cc @rspeicher @DouweM 

See merge request !2725

app/controllers/admin/broadcast_messages_controller.rb

@@ -2,7 +2,7 @@ class Admin::BroadcastMessagesController < Admin::ApplicationController
   before_action :finder, only: [:edit, :update, :destroy]
   def index
-    @broadcast_messages = BroadcastMessage.reorder("starts_at ASC").page(params[:page])
+    @broadcast_messages = BroadcastMessage.reorder("ends_at DESC").page(params[:page])
     @broadcast_message  = BroadcastMessage.new
   end

app/views/admin/broadcast_messages/index.html.haml

@@ -34,4 +34,4 @@
             = link_to icon('pencil-square-o'), edit_admin_broadcast_message_path(message), title: 'Edit', class: 'btn btn-xs'
             = link_to icon('times'), admin_broadcast_message_path(message), method: :delete, remote: true, title: 'Remove', class: 'js-remove-tr btn btn-xs btn-danger'
-  = paginate @broadcast_messages
+  = paginate @broadcast_messages, theme: 'gitlab'