[ADD] First commit of publication_management module.
[ADD] Added website_sale_attachments_timestamp module.
[IMP] 8.0-website_sale_attachments_timestamp: added tests.
[IMP] website_sale_attachments_timestamp: fixed the str.format() usage.
[IMP] website_sale_attachments_timestamp: fixed the unittest.
Merge branch '8.0-website_sale_attachments_timestamp' of https://github.com/savoirfairelinux/edition-mgmt into 8.0-website_sale_attachments_timestamp