Use assertRaises instead of try/except/else
Use assertRaises instead of try/except/else

Change-Id: I8b1105404511c003e032f03777ce85325abbe0cd

rdo-management/python-heatclient,jasondunsmore/python-heatclient,metacloud/python-heatclient,rdo-management/python-heatclient,tcpcloud/python-heatclient,varunarya10/python-heatclient,metacloud/python-heatclient,ecerulm/python-heatclient,varunarya10/python-heatclient,ecerulm/python-heatclient,jasondunsmore/python-heatclient,openstack/python-heatclient,tcpcloud/python-heatclient