Allow passing a "insecure" flag in trusts

[OpenStack Infra]

https://review.openstack.org/348045
Dear bug triager. This bug was created since a commit was marked with DOCIMPACT.
Your project "openstack/magnum" is set up so that we directly report the documentation bugs against it. If this needs changing, the docimpact-group option needs to be added for the project. You can ask the OpenStack infra team (#openstack-infra on freenode) for help if you need to.

commit c5950ca24cd97023c576723080f2b433fe25ae96
Author: Abhishek Chanda <email address hidden>
Date: Wed Jul 27 14:17:13 2016 -0700

    Allow passing a "insecure" flag in trusts

    Keystone deployments can be on self signed certs, which will fail
    on verifying the cert on client side. This patch allows an user
    to turn off cert verification.

    Partially-Closes: #1597995

    DocImpact

    Change-Id: I1e1298b96ea6ec499f55230325c867b81d38a243

[hongbin (hongbin034)]

Keep in mind that the patch was submitted to stable/mitaka only. Therefore, the addition of docs should be submitted to mitaka as well.