## Changes
This PR sets "resource" to nil in the terraform representation if no
resources are defined in the bundle configuration. This solves two
problems:
1. Makes bundle deploy work without any resources specified.
2. Previously if a `resources` block was removed after a deployment,
that would fail with an error. Now the resources would get destroyed as
expected.
Also removes `TerraformHasNoResources` which is no longer needed.
## Tests
New e2e tests.