Run now takes a context as well as a statebag. We'll assign the context
to the blank identifier to prevent namespace collisions. We'll let the
step authors opt-in to using the context.
`find . -iname "step_*.go" -exec gsed -i'' 's/func \(.*\)Run(/func \1Run(_ context.Context, /' {} \;`
This commit adds a new type of builder which builds an AMI based on a
snapshot of an EBS volume which is provisioned on a "surrogate"
instance. This can be used to build operating system images from
scratch, but unlike the `chroot` builder does not require running from
an AWS EC2 instance.