A failing script in a `remote-exec` provisioner's `inline` stanza
won't fail the provisioning step. This lets us continue on to execute
tests against potentially broken deployments, rather than letting us
know the provisioning itself failed.
When multiple developers are working on e2e testing, it helps to be
able to identify which infrastructure belongs to which Nomad SHA and
which developer. This adds tags to the EC2 instances.
