Fix minor problems identified in recent pagination work

[Jim Baker]

The pagination code is important, and touching a lot of things. Given tight deadlines, etc, etc, and to ensure it got sequenced in the development, I approved this change. But please fix the minors identified by Thomas Maddox and me:

https://review.openstack.org/#/c/426229/11

Thanks!

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/434506

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/434506
Committed: https://git.openstack.org/cgit/openstack/craton/commit/?id=462c501b13e0510c69a742141f809a21a141685a
Submitter: Jenkins
Branch: master

commit 462c501b13e0510c69a742141f809a21a141685a
Author: Ian Cordasco <email address hidden>
Date: Wed Feb 15 14:40:48 2017 -0600

    Add sort_dir and sort_keys to endpoint schemata

    sort_dir and sort_keys are used in the pagination work. Adding them to
    the schemata allows users to specify them in their queries without
    receiving 400 Bad Request errors.

    Change-Id: If743958afc578be0ffa48c9b0a2670f76855424c
    Partial-Bug: #1664786
    Implements: bp pagination-of-resources

[Ian Cordasco (icordasc)]

I believe this was fixed. If not we can fix the status.