Get the test env overcloud password from the correct place
Get the test env overcloud password from the correct place

This was in the current working directory from where devtest was run,
it has recently explicitly been given a home in TRIPLEO_ROOT.

Change-Id: I89c01345840fef770b3db493b477d5358d8c1237

radez/tripleo-image-elements,openstack/tripleo-image-elements,radez/tripleo-image-elements,rdo-management/tripleo-image-elements,rdo-management/tripleo-image-elements,openstack/tripleo-image-elements