Add logging to permission removal Rake task

This Rake task didn't have any count logging, so in order to be sure it
worked, you'd have to run some of the code after (and also ideally
before) running the Rake task to check the permission counts. This task
has already been run, but we may reuse it in future and/or use it as a
template for other similar Rake tasks, so we should make it more of a
best practice example now

lib/tasks/permissions.rake

@@ -27,11 +27,21 @@ namespace :permissions do
       supported_permission: whitehall_managing_editor_permission,
       user_id: User.where.not(organisation_id: gds.id),
     ).pluck(:user_id)
-    user_editor_permissions_to_destroy_ids = UserApplicationPermission.where(
+    editor_permissions_to_destroy = UserApplicationPermission.where(
       supported_permission: whitehall_editor_permission,
       user_id: non_gds_users_with_managing_editor_permission_user_ids,
     )
 
-    user_editor_permissions_to_destroy_ids.destroy_all
+    puts "Number of non-GDS users with both managing editor and editor permissions in Whitehall"
+    puts "Before removing permissions: #{editor_permissions_to_destroy.count}"
+
+    editor_permissions_to_destroy.destroy_all
+
+    count_of_remaining_users_with_both_permissions = UserApplicationPermission.where(
+      supported_permission: whitehall_editor_permission,
+      user_id: non_gds_users_with_managing_editor_permission_user_ids,
+    ).count
+
+    puts "After removing permissions: #{count_of_remaining_users_with_both_permissions}"
   end
 end