Add REST API to get single bay
Add REST API to get single bay

This patch adds REST API to get single bay using bay-show
of magnumclient.

Change-Id: I07e936257211d699d2a416b7c4a5ecf16e6db06b
Implements: blueprint bay-api

openstack/magnum-ui,openstack/magnum-ui,openstack/magnum-ui,openstack/magnum-ui