Hide stderr noise in test output
Hide stderr noise in test output

Previously, some tests caused the usage options for glance to be printed out to
stderr. This patch redirects the stderr output for those unnecessarily verbose
test functions.

Change-Id: I781d35a16a97c9c093cb17288ebd96d3e1a2e4e9
Closes-Bug: #1334655

mmasaki/python-glanceclient,alexpilotti/python-glanceclient,varunarya10/python-glanceclient,klmitch/python-glanceclient,varunarya10/python-glanceclient,alexpilotti/python-glanceclient,mmasaki/python-glanceclient,openstack/python-glanceclient,JioCloud/python-glanceclient,JioCloud/python-glanceclient,klmitch/python-glanceclient,openstack/python-glanceclient