Remove deprecated methods from assignment manager

[Brant Knudson]

The assignment manager doesn't provide a stable interface (yet), so there's no need to go through deprecation.

Also, leaving the deprecated methods around makes it too easy for developers of new features to use the old deprecated method rather than the new one.

[Brant Knudson (blk-u)]

https://review.openstack.org/#/c/210174/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/210174
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=c7f2ec44b9f0d813b838459817c25f1fe3007b5e
Submitter: Jenkins
Branch: master

commit c7f2ec44b9f0d813b838459817c25f1fe3007b5e
Author: Brant Knudson <email address hidden>
Date: Thu Aug 6 20:04:31 2015 -0500

    Remove deprecated methods from assignment.Manager

    assignment.Manager provided several methods that forwarded calls to
    the role and resource managers. These are removed.

    assignment.Manager's interface isn't stable anyways so there was
    no need to mark these as deprecated.

    DocImpact
    ReleaseNoteImpact

    Closes-Bug: 1482662
    Change-Id: Ie2340a2fd0e7acef4e285db23a575ee5824513b9