Bug: Properly interface with Dalli client

[tstone]

Background

The Dalli storage adapter appears to incorrectly assume the adapter is Rails.cache instead of the actual Dalli client. This PR changes it to expect the Dalli client.

Tasks

• Code of Conduct reviewed
• Specs written and passing
• Backwards-incompatible changes called out in this PR
• Increment the version file (./lib/atomic_cache/version.rb) when applicable
  • See semver.org for what segment to increment

[lebeerman]

This makes sense to me. Only additional though around if atomic_cache should expect a default ttl when using a Dalli client when the :expires_in option is used on init. Guess this is more specific than the gem needs to be? (e: per DM - 👍 Dalli owns the default value behavior)