OpenStack.get_value(): Be case-insensitive.
OpenStack.get_value(): Be case-insensitive.

Signed-off-by: Zack Cerza <d7cdf09fc0f0426e98c9978ee42da5d61fa54986@redhat.com>

caibo2014/teuthology,ktdreyer/teuthology,ktdreyer/teuthology,robbat2/teuthology,SUSE/teuthology,ceph/teuthology,dmick/teuthology,dmick/teuthology,SUSE/teuthology,dreamhost/teuthology,robbat2/teuthology,dreamhost/teuthology,ceph/teuthology,caibo2014/teuthology,SUSE/teuthology,dmick/teuthology