[refs #232] Add edit btn to group public page

app/views/groups/show.html.haml

@@ -7,6 +7,8 @@
     - @group.projects.each do |project|
       = link_to project.name, project
       %br
+  %br
+  = link_to t("layout.edit"), edit_group_path(@group), :class => 'button' if can? :edit, @group
 
 -#.block
 -#  .secondary-navigation