Fully implement bay object in ReST API

The bay object is implemented in the ReST API.  The rest of the stack
needs implementation.

At the moment it is possible to use the following bay operations:

* bay-create
* bay-delete
* bay-list
* bay-get

Change-Id: I19a2ebd4bcca4e21785e6b6ebfb7db79a6e9f1d9