Added navigation link to Sherlock

app/views/layouts/header/_default.html.haml

@@ -21,6 +21,11 @@
             %li
               = link_to new_project_path, title: 'New project', data: {toggle: 'tooltip', placement: 'bottom'} do
                 = icon('plus fw')
+          - if Gitlab::Sherlock.enabled?
+            %li
+              = link_to sherlock_transactions_path, title: 'Sherlock Transactions',
+                data: {toggle: 'tooltip', placement: 'bottom'} do
+                = icon('tachometer fw')
           %li
             = link_to destroy_user_session_path, class: 'logout', method: :delete, title: 'Sign out', data: {toggle: 'tooltip', placement: 'bottom'} do
               = icon('sign-out')