no issue
This pull request removes the `suppressionList` feature flag and all its
dependencies from the codebase. It makes the suppression list feature
the default and consistent behavior for all email events and
newsletters. It simplifies the UI, logic, and data related to email
events and newsletters. It affects several files in the
`ghost/admin/app`, `ghost/core/core`, and `ghost/members-api`
directories.
refs TryGhost/Team#2371
- check that members can unsubscribe from newsletters by toggling
preferences in their account settings
- check that member can log out
refs https://github.com/TryGhost/Team/issues/1492
Allows site owners to manage member's newsletter preference directly in Admin.
- also adds `visibility` property for newsletter model
- updates members test model to include `visibility`
