We have two CLIs: zuul-client for REST-related operations, which cover
tenant-scoped, workflow modifying actions such as enqueue, dequeue and
promote; and zuul which supercedes zuul-client and covers also true admin
operations like ZooKeeper maintenance, config checking and issueing auth tokens.
This is a bit confusing for users and operators, and can induce code
duplication.
* Rename zuul CLI into zuul-admin. zuul is still a valid endpoint
and will be removed after next release.
* Print a deprecation warning when invoking the admin CLI as zuul
instead of zuul-admin, and when running autohold-*, enqueue-*,
dequeue and promote subcommands. These subcommands will need to be
run with zuul-client after next release.
* Clarify the scopes and deprecations in the documentation.
Change-Id: I90cf6f2be4e4c8180ad0f5e2696b7eaa7380b411
57c78c08e1