Support non-admin ems refresh users - OpenstackHandle

OpenStack handle changes required to support ems refresh
using non-admin credentials.
Support non-admin ems refresh users - openstack parser

Openstack parser changes required to support ems refresh
using non-admin credentials.
Support non-admin ems refresh users - test

Test changes required to support ems refresh
using non-admin credentials.
Updates based on code review comments.
Changes based on code review comments.
Merge pull request #681 from roliveri/openstack_tenant

Support non-admin ems refresh users