Fix ChefSpec matchers to use new method

[martinisoft]

Consumers of this cookbook in ChefSpec are getting the following deprecation warning:

[DEPRECATION] `ChefSpec::Runner.define_runner_method' is deprecated. It is being used in the stunnel_connection resource matcher. Please use `ChefSpec.define_matcher' instead. (called from spec/unit/recipes/default_spec.rb:15:in `block (3 levels) in <top (required)>')

[damacus]

For traige: This issue needs a better description of what a solution looks like.

[github-actions]

Marking stale due to inactivity. Remove stale label or comment or this will be closed in 7 days. Alternatively drop by the #sous-chefs channel on the Chef Community Slack and we'll be happy to help! Thanks, Sous-Chefs.