[docs] Update quickstart guide to use bay-config command

[hongbin]

This patch added support for bay-config command to configure native client: https://review.openstack.org/#/c/342153/ . However, the quickstart guide (http://docs.openstack.org/developer/magnum/dev/quickstart.html#using-kubernetes-bay) hasn't been updated to use this command yet. The guide should be updated to use magnum bay-config command.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/398153

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/398153
Committed: https://git.openstack.org/cgit/openstack/magnum/commit/?id=467f8fa2bc84f80e594c9b4f6f1f1c2d9d487231
Submitter: Jenkins
Branch: master

commit 467f8fa2bc84f80e594c9b4f6f1f1c2d9d487231
Author: Hieu LE <email address hidden>
Date: Wed Nov 16 14:30:39 2016 +0700

    [docs]Update quickstart guide to use cluster-config command

    Magnum CLI now support cluster-config command. However, the quickstart guide
    hasn't been updated to use this command yet. This patch added usage for
    cluster-config command in quickstart guide.

    Change-Id: I21341fe90c09f8f21e33bda4592c9175f3d16375
    Closes-Bug: #1614685

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/magnum 4.0.0 release.