Currently Session Persistance for a pool can be cleared by
"neutron lbaas-pool-update pool --session-persistence type=dict type=NONE"
But this option seems to be a bit long and complicated, so
therefore this patch tries to simplify it by adding a new
option --no-session-persistence, which does the same job.
Change-Id: Iacafe765a2f0f9537a4e4d01b9b8086a9e313b92
Depends-On: I654b172927e1d96677a7da9e0846231b0ac48aa9