Reasons for making this change:

As stated in Symfony documentation, all " log and cache files and dumped assets (which are created automatically by your project), should not be committed in Git.". Spool folder only contains files created by running the application, since they are files to be sent.

Links to documentation supporting these rule changes:

http://symfony.com/doc/current/cookbook/workflow/new_project_git.html

@nunorafaelrocha Is there any supporting links you can give which explain what this file represents and why it can be safely ignored from version control?

@shiftkey Updated PR description to add the necessary information.

@nunorafaelrocha fantastic, thanks!