Move MR alert info out of issue-box

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

app/views/projects/merge_requests/show/_mr_box.html.haml

@@ -25,20 +25,20 @@
         = preserve do
           = markdown @merge_request.description
 
-  - if @merge_request.closed?
-    .description
+- if @merge_request.closed?
+  .alert.alert-info
     %span
       %i.icon-remove
       Closed by #{link_to_member(@project, @merge_request.closed_event.author)}
       #{time_ago_with_tooltip(@merge_request.closed_event.created_at)}.
-  - if @merge_request.merged?
-    .description
+- if @merge_request.merged?
+  .alert.alert-info
     %span
       %i.icon-ok
       Merged by #{link_to_member(@project, @merge_request.merge_event.author)}
       #{time_ago_with_tooltip(@merge_request.merge_event.created_at)}.
-  - if !@closes_issues.empty? && @merge_request.opened?
-    .description.alert-info
+- if !@closes_issues.empty? && @merge_request.opened?
+  .alert.alert-info.alert-info
     %span
       %i.icon-ok
       Accepting this merge request will close #{@closes_issues.size == 1 ? 'issue' : 'issues'}