Update feed to use published attribute.
Update feed to use published attribute.

mozmar/snippets-service,glogiotatidis/snippets-service,mozilla/snippets-service,mozilla/snippets-service,glogiotatidis/snippets-service,mozilla/snippets-service,mozmar/snippets-service,glogiotatidis/snippets-service,mozilla/snippets-service,mozmar/snippets-service,glogiotatidis/snippets-service,mozmar/snippets-service