Add test for cinder with VMDK backend
Add test for cinder with VMDK backend

- implement following testing scenario:
  * create a cluster
  * add one controller and one cinder node (VMDK backend)
  * deploy the cluster in one go
  * run OSTF
- do not import whole fuelweb_test.settings module, instead import only
  those variables that are needed for tests

Change-Id: Ib8d29f5d6477ca5adf2c5364aa829b63c2568e4b
Closes-bug: #1368285

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