feat(contrib): add DigitalOcean provisioner booting CoreOS via kexec

This introduces a provisioning script for Deis on DigitalOcean droplets. As DigitalOcean
does not (currently) support CoreOS, we deploy CoreOS on top of Ubuntu 14.04 using kexec
on boot to switch to the CoreOS kernel and initrd. The state filesystem is a loop
mounted btrfs.

The CoreOS bootstrapping is heavily based on Levi Aul's code:

  https://gist.github.com/tsutsu/490f35f48897df0f5173

We don't use Debian 7.0 as base distribution because kexec is unstable on the Debian
kernel.
refactor(contrib/digitalocean): clean up README, act more like other contrib/ scripts

Updates the README to flow more like the other contrib/ scripts.
Also adds a provision-do-cluster.sh
chore(contrib/digitalocean): make NYC2 the default region
Merge pull request #1217 from deis/do

feat(contrib): add DigitalOcean provisioner booting CoreOS via kexec
fix(integration): modify client to take input from stdin

To test the gexpect feature but g expect is not working so reverted the change
fix(client): change account spelling in deis auth cancel
test(integration): add basic working framework files
fix(client): change account spelling in deis auth cancel
test(integration): working versions of auth and keys commands
test(integration) : vendor json library and adjust indentation
test(integration) : working integration tests

Vendored Gexpect
test(integration) : minor bug fixes