Add new style to "New group" button

The new group button style was changed to have the same look as the new
project button (green background).

app/assets/stylesheets/sections/dashboard.scss

@@ -120,6 +120,15 @@
   }
 }
+.dash-new-group {
+  background: $bg_success;
+  border: 1px solid $border_success;
+
+  a {
+    color: #FFF;
+  }
+}
+
 .dash-list .str-truncated {
   max-width: 72%;
 }

app/views/dashboard/_groups.html.haml

@@ -3,7 +3,7 @@
     .input-group
       = search_field_tag :filter_group, nil, placeholder: 'Filter by name', class: 'dash-filter form-control'
       - if current_user.can_create_group?
-        .input-group-addon
+        .input-group-addon.dash-new-group
           = link_to new_group_path, class: "" do
             %strong New group
   %ul.well-list.dash-list