Incorrect error code for unathorized policy on all_tenants and edit_managed attributes

[Rudrajit Tapadar]

When using the --all-tenants or --edit-managed attributes for a user who doesn't have the privileges to run those attributes, designate fails with a 500 error. This should be a Forbidden (403) error.

The api.middleware unit tests should be updated to take care of the negative cases as well.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/223062

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/223062
Committed: https://git.openstack.org/cgit/openstack/designate/commit/?id=f51ce400348bb9f9cca2fa1490ffb7cebdfbddee
Submitter: Jenkins
Branch: master

commit f51ce400348bb9f9cca2fa1490ffb7cebdfbddee
Author: hardik <email address hidden>
Date: Mon Sep 14 15:59:07 2015 +0530

    Handling Forbidden Exception

    This patch adds forbidden exception for all_tenants
    and edit_managed attributes.

    Change-Id: I7a160abee99cc787f18593cba5c9e33485a85239
    Closes-Bug: #1486709

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/kilo
Review: https://review.openstack.org/224212

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/224212
Committed: https://git.openstack.org/cgit/openstack/designate/commit/?id=3b2e61a76468dda14afad07f5899863810e2adf4
Submitter: Jenkins
Branch: stable/kilo

commit 3b2e61a76468dda14afad07f5899863810e2adf4
Author: hardik <email address hidden>
Date: Mon Sep 14 15:59:07 2015 +0530

    Handling Forbidden Exception

    This patch adds forbidden exception for all_tenants
    and edit_managed attributes.

    Change-Id: I7a160abee99cc787f18593cba5c9e33485a85239
    Closes-Bug: #1486709
    (cherry picked from commit f51ce400348bb9f9cca2fa1490ffb7cebdfbddee)