Move ‘send test’ link back to template page

This changes it back to how it was when we first introduced this
feature:
https://github.com/alphagov/notifications-admin/pull/181

It’s kind of lost on the page where you upload a file, which is a shame
because it’s a good teaching aid.

app/templates/views/send.html

@@ -35,9 +35,7 @@
   <div class="page-footer bottom-gutter">
     {{file_upload(
       form.file,
-      button_text='Upload a file of recipients',
-      alternate_link=url_for(".send_test", service_id=current_service.id, template_id=template.id),
-      alternate_link_text='send yourself a test'
+      button_text='Upload a file of recipients'
     )}}
   </div>