[queues] Return shard listing as object, not array

[Allele Dev]

Return the array encapsulated in an object (e.g., {}). This will allow for extensions and adding fields that won't break backwards-compatibility.

Currently, it is returned as an array.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/50998
Committed: http://github.com/openstack/marconi/commit/f6c321dd8b3f4f921c3cbf82fc385bb6e71cf9c0
Submitter: Jenkins
Branch: master

commit f6c321dd8b3f4f921c3cbf82fc385bb6e71cf9c0
Author: Alejandro Cabrera <email address hidden>
Date: Thu Oct 10 09:12:53 2013 -0400

    feat: integrate shard storage with transport

    This patch refines the interface and storage implementation defined in
    the last patch and integrates it with the transport layer.

    A few updates have been made:
    - 'name' -> 'href' for listing shards
    - limiting, markers, and detailed are all used
    - use of common_utils.fields to clean up shards transport PATCH
    - add missing init for schemas
    - fix schema issues found: 'location' -> 'uri', __init__.py
    - shard resource correctly implements PUT semantics (replaces)

    Transport: the admin API concept has been expanded to include
    functionality from the public interface *in addition* to admin
    functionality. Part of the rationale behind this is to simplify unit
    testing. The other part of this is that an admin should be able to do
    everything a normal user can do in addition to their special
    functions.

    Storage: now divided into control and data plane. The bootstrap passes
    a control driver down to the transport which *can* be used for
    endpoints as needed.

    A test suite has been added that exercises the functionality from the
    transport side of the shard registry resource.

    Finally, the way the FaultyStorage driver tests were handled was
    changed. Something about the setattr magic in that suite's setup made
    it such that *all* tests would use the Faulty storage driver. This is
    possibly related to the use of lazy_property decorators. To address
    this issue, this patch promotes the faulty storage driver to setup.cfg
    visibility and removes the setattrs.

    Change-Id: I5b8cdb3a11d29422762b52f1e15e33167eecb867
    Partitally-implements: blueprint storage-sharding
    Partially-Closes: 1241686
    Closes-Bug: 1243898