⚙️ Bumped required Ghost-CLI version to 1.16.0
⚙️ Bumped required Ghost-CLI version to 1.16.0

no issue

- Ghost-CLI 1.16.0 contains changes required for the new Ghost 4.0 boot
  - see release notes: https://github.com/TryGhost/Ghost-CLI/releases/tag/1.16.0
- we've also implemented a new policy that you must be on the latest
  version of your major in order to major migrate, which is handled in
  this new CLI version
- by bumping it here, users on previous versions will be required to
  update CLI when attempting to upgrade Ghost

TryGhost/Ghost,TryGhost/Ghost,ErisDS/Ghost,janvt/Ghost,ErisDS/Ghost,e10/Ghost,bitjson/Ghost,e10/Ghost,bitjson/Ghost,janvt/Ghost,ErisDS/Ghost,TryGhost/Ghost