Bump python-swiftclient version

[OpenStack Infra]

https://review.openstack.org/75927
commit c93a7a22c02b5b95c85027da3a26e5f378b8f1f2
Author: Thomas Leaman <email address hidden>
Date: Mon Feb 24 17:03:33 2014 +0000

    Bump python-swiftclient version

    https://review.openstack.org/#/c/69187/ introduced SSL certificate checking
    in python-swiftclient (released as v2.0). This patch ensures that the version
    of swiftclient used will verify SSL certificates correctly.

    This patch also documents the `swift_store_auth_insecure` configuration
    option for bypassing the cert verification

    DocImpact
    SecurityImpact

    Change-Id: I20ddab5c3359071daf7505268c72331e4c786987

[Tom Fifield (fifieldt)]

This should be picked up in the next run of autodoc tools