Instead of pulling the plug on a droplet with the "poweroff" command,
we first send a soft shutdown to the API, then we poweroff to allow
the snapshot to properly complete.
Sending just a shutdown and then snapshotting wasn't as reliable as
sending the poweroff manually, for reasons unknown to me.
This fixes#332.
The state_timeout config allows you to determine the timeout
for "waiting for droplet to become [active, off, etc.]".
This still defaults to 3 minutes.
Jack Pearkes
Mitchell Hashimoto