VMware: expose boolean insecure for certificate verification

[Eric Brown]

Commit Ida730db66b154a4d445f7a91bccb9ca5b5a26f5e introduced certificate verification but did not expose the option to turn
on/off verification using the insecure boolean.

 It's actually more beneficial to have trusted certificates loaded into the operating systems ca-certificate store and verify using that instead of specifying a location to a cert file.

Therefore, the 'insecure' option of oslo_vmware should be exposed in the cinder vmware driver.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/179991

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/179991
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=9240fef1b29fefd125a3e5c0066fe9a89519437c
Submitter: Jenkins
Branch: master

commit 9240fef1b29fefd125a3e5c0066fe9a89519437c
Author: Eric Brown <email address hidden>
Date: Mon May 4 18:42:48 2015 -0700

    VMware: insecure option should be exposed

    Commit Ida730db66b154a4d445f7a91bccb9ca5b5a26f5e introduced
    certificate verification but did not expose the option to turn
    on/off verification using the insecure boolean of oslo.vmware.

    DocImpact

    Change-Id: I834c9fb407c8790dab14db0308f7e7f1d551669e
    Closes-Bug: #1451633