Barry Gordon

Follows up on https://github.com/dependabot/dependabot-core/pull/5142 This PR switches Terraform over to use the `Dependabot::RegistryClient` so it benefits from caching of unreachable hosts. ~~Since this gem implements `Dependabot::Terraform::RegistryClient`, I incorporated the caching...

It's very easy to pass minor typos like `ignored_adapter` instead of `ignored_adapters` without meaningful feedback. Validation of the options being passed, along with echoing configuration to the user in output...