Style dashboard milestones page

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

app/views/dashboard/milestones/index.html.haml

 - page_title "Milestones"
 - header_title  "Milestones", dashboard_milestones_path
 
-%p.light
-  List all milestones from all projects you have access to.
-
 
 = render 'shared/milestones_filter'
+
+.gray-content-block
+  .oneline
+    List all milestones from all projects you have access to.
+
 .milestones
-  .panel.panel-default
-    %ul.well-list
-      - if @dashboard_milestones.blank?
-        %li
-          .nothing-here-block No milestones to show
-      - else
-        - @dashboard_milestones.each do |milestone|
-          = render 'milestone', milestone: milestone
+  %ul.content-list
+    - if @dashboard_milestones.blank?
+      %li
+        .nothing-here-block No milestones to show
+    - else
+      - @dashboard_milestones.each do |milestone|
+        = render 'milestone', milestone: milestone
   = paginate @dashboard_milestones, theme: "gitlab"

app/views/shared/_milestones_filter.html.haml

-.milestones-filters.append-bottom-10
-  %ul.nav.nav-tabs
+.milestones-filters
+  %ul.center-top-menu
     %li{class: ("active" if params[:state].blank? || params[:state] == 'opened')}
       = link_to milestones_filter_path(state: 'opened') do
         %i.fa.fa-exclamation-circle