* Add consumable invites
* Add UI for generating invite codes
* Add tests
* Display max uses and expiration in invites table, delete invite
* Remove unused column and redundant validator
- Default follows not used, probably bad idea
- InviteCodeValidator is redundant because RegistrationsController
checks invite code validity
* Add admin setting to disable invites
* Add admin UI for invites, configurable role for invite creation
- Admin UI that lists everyone's invites, always available
- Admin setting min_invite_role to control who can invite people
- Non-admin invite UI only visible if users are allowed to
* Do not remove invites from database, expire them instantly
When a new user confirms their e-mail, bootstrap their home timeline
by automatically following a set of accounts. By default, all local
admin accounts (that are unlocked). Can be customized by new admin
setting (comma-separated usernames, local and unlocked only)
