Modify for gluster pool and volume test

Add support for gluster pool and volume test, include cleanup env steps
Yes, that's the right way. And i agree with you that we should keep the arguments as less as possible, this func defined here is help uers can define a pool conveniently.
So for  gluster type pool, chould we deal with it like the NFS or iSCSI way, just using some default values in ```setup_or_cleanup_gluster```define the pool?