Confirm Rackspace server destruction.

[dkinzer]

This pull request implements a fix for #114

[maxlinc]

Wow... I got so used to typing "vagrant destroy -f" I never even noticed the -f didn't matter.

@smashwilson LGTM. Should be backwards compatible all the way back to Vagrant 1.2.2.

[smashwilson]

@smashwilson LGTM. Should be backwards compatible all the way back to Vagrant 1.2.2.

Good enough for me!

[dkinzer]

@maxlinc yeah, I was rather surprised too, and completely caught off guard.

I had set up a multi environment Vagrantfile and I needed to shed some VM weight off. I was relying on the confirmation to skip stuff I actually wanted to keep around and then the Rackspace stuff just disappeared without any confirmation. Ugh.

Fortunately it wasn't too much of a hassle to spin up the server again an get it provisioned, but I still...

[dkinzer]

@smashwilson I noticed that this was asking but not actually skipping so UI forced pushed "fix" but it's wrong ... I need to redo ... sorry, thought I had time to fix it before anyone would merge it.

[dkinzer]

I.e I forgot to require

uninitialized constant VagrantPlugins::Rackspace::Action::MessageWillNotDestroy