Switch to none auth for standalone mode

https://review.openstack.org/359061
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commit 58c39b7a80583dd54165cf292ae5dc621e9da361
Author: Vladyslav Drok <email address hidden>
Date: Tue Aug 23 12:13:23 2016 +0300

    Switch to none auth for standalone mode

    Currently, during the ironic shell client construction, if only
    os_auth_token and endpoint arguments are passed, custom
    HTTPClient class based on requests' sessions is used. This is
    unnecessary, as there is admin_token auth type in keystoneauth
    that does basically the same, eliminating the need for our
    custom implementation. Apart from that, there is a none auth,
    which requires only passing the desired endpoint to use, so we
    can use it too without having to specify fake token strings
    anymore. Let's use these auth methods instead and deprecate
    HTTPClient.

    Also this patch deprecates a bunch of arguments to client.get_client
    function, changing them to the standard keystoneauth naming.

    DocImpact
    Story: 1696791
    Task: 11836
    Depends-On: https://review.openstack.org/559116
    Change-Id: Ifc7b45d047c8882a41021e1604b74d17eac2e6e8