Can you refactor this to use the RSpec 3 matchers and new syntax we are moving toward?

A few things:

- Do not start `it` blocks with "should". Declare instead
- Don't use `should` prefix. Use `expect()` syntax instead
- Follow [this kind of pattern](https://github.com/acrmp/chefspec/pull/209/files#L21R6) for testing a resource matcher