Force detach should only be an admin api

Since force delete volume apis are only admin apis, force detach volume api
should also be an admin only api.  Currently, the force detach api,
which uses the default rule in policy.json, can be called by admins and owners.
This patch make force detach volume api an admin only api like force
delete volume.

Closes-Bug: #1303882
Change-Id: I12f927e816a5ba6809da9a27ac4ad150546286a1
Switch over to FixedIntervalLoopingCall

Change-Id: Iebe5269ea01acdd4ba011742831ca5e569f66b28
Closes-Bug: #1307560
Storwize/SVC driver crashes when check volume copy status

Storwize/SVC driver does not clear up property of _vdiskcopyops
when deleting a volume. So if a volume which under async copy is
deleted before sync completed, the driver will crash.

When delete a volume, add a check for _vdiskcopyops, if volume
is in the dict, remove it.

Change-Id: I4905404b72a7ac8f90bd92fa4345ba771a78418b
Closes-Bug: #1304115
Merge "Storwize/SVC driver crashes when check volume copy status"
Merge "Force detach should only be an admin api"
Merge "Switch over to FixedIntervalLoopingCall"