Take screenshots only on test failures
Take screenshots only on test failures

Change-Id: I63a3bc105cba1a7be6a478a5054de2cd35bc93c4

eayunstack/fuel-web,stackforge/fuel-web,eayunstack/fuel-web,eayunstack/fuel-web,huntxu/fuel-web,SmartInfrastructures/fuel-web-dev,eayunstack/fuel-web,huntxu/fuel-web,SmartInfrastructures/fuel-web-dev,huntxu/fuel-web,eayunstack/fuel-web,SmartInfrastructures/fuel-web-dev,huntxu/fuel-web,huntxu/fuel-web,stackforge/fuel-web,stackforge/fuel-web,SmartInfrastructures/fuel-web-dev,SmartInfrastructures/fuel-web-dev