Redis cache adaptor

This PR adds the required methods to implement the Redis cache adaptor 🎉

Add cache cleaner process

This release introduces functionality which adds a cleaner process that runs in an isolated go-routine, this process clears stale cache items inside the cache.

Initial release

This is the first release of the small opinionated go cache 🎉

In this release a simple in-memory cache solution is implemented, more cache adaptors to follow and useful methods on the cache adaptors.