Update system test requirements
Update system test requirements

    Change devops version to 2.5.5

Change-Id: I9e5b33f6020705dcb4b008c930a30350d9f136ed
Related-bug: #1420459

teselkin/fuel-main,Fiware/ops.Fuel-main-dev,dancn/fuel-main-dev,huntxu/fuel-main,Fiware/ops.Fuel-main-dev,eayunstack/fuel-main,teselkin/fuel-main,SergK/fuel-main,AnselZhangGit/fuel-main,eayunstack/fuel-main,teselkin/fuel-main,AnselZhangGit/fuel-main,zhaochao/fuel-main,dancn/fuel-main-dev,dancn/fuel-main-dev,stackforge/fuel-main,ddepaoli3/fuel-main-dev,dancn/fuel-main-dev,zhaochao/fuel-main,zhaochao/fuel-main,Fiware/ops.Fuel-main-dev,ddepaoli3/fuel-main-dev,Fiware/ops.Fuel-main-dev,SmartInfrastructures/fuel-main-dev,SergK/fuel-main,SmartInfrastructures/fuel-main-dev,zhaochao/fuel-main,SmartInfrastructures/fuel-main-dev,AnselZhangGit/fuel-main,zhaochao/fuel-main,huntxu/fuel-main,teselkin/fuel-main,stackforge/fuel-main,SmartInfrastructures/fuel-main-dev,AnselZhangGit/fuel-main,stackforge/fuel-main,ddepaoli3/fuel-main-dev,SergK/fuel-main,ddepaoli3/fuel-main-dev,eayunstack/fuel-main,huntxu/fuel-main