[Fix #494] If super-admin is connected, add an link in the header menu

app/assets/images/icons/super-admin.svg

@@ -0,0 +1 @@
+<svg width="25" height="25" viewBox="0 0 25 25" xmlns="http://www.w3.org/2000/svg"><title>Shape</title><path d="M20.37.5H4.946L.7 6.19l12 18.31 12-18.31L20.37.5zm2.355 5.69l-2.98 4.541c0-.006-.005-.011-.005-.011-.39-.975-.853-2.648-4.215-3.026 0 0-5.351.321-6.377-.563-1.025-.885-2.917-3.132 1.417-4.58 2.635-.885 5.716.377 5.998 3.887h3.488V2.213l2.674 3.977zM8.253 14.49a.148.148 0 0 0-.021.034L5.84 10.877l.005-.01s.912.732 4.232.884c3.32.146 6.25.146 7.158 1.087.912.94-.769 2.704-4.791 2.462-.005 0-2.257-3.606-4.19-.811zM18.311 2.19s.21 1.578-.756 1.972c0 0-.084-.355-1.207-1.972h1.963zm-12.735 0h2.45c-.454.192-3.657 1.989-3.417 6.8v.023L2.759 6.19l2.817-4zm4.073 14.496c.004 0 4.85.715 6.212-.186.059-.04.117-.079.18-.13l-3.299 5.031-3.093-4.715z" fill-rule="nonzero" fill="#4393F3"/></svg>

app/views/layouts/_new_header.haml

@@ -27,7 +27,11 @@
               %li
                 .menu-item{ title: current_email }
                   = current_email
-
+              - if administration_signed_in?
+                %li
+                  = link_to administrations_path, class: "menu-item menu-link" do
+                    = image_tag "icons/super-admin.svg"
+                    Passer en super-admin
               - if SwitchDeviseProfileService.new(warden).multiple_devise_profile_connect?
                 - if user_signed_in?
                   %li