Update to Rack 2.0.8

This release adds support for Rack v2.0.8+, which was released a few weeks ago to address a session hijack vulnerability caused by a timing attack on the session store. Major shoutouts to @le0pard for implementing it and all of the reviewers who contributed suggestions and comments. If you use Redis to store your Rack session, you'll want to update redis-rack and possibly redis-actionpack if you're using Rails as well.

Support New Rack APIs

This changes the underlying API from using the legacy Rack::Session::Abstract::ID to Rack::Session::Abstract::Persisted, in order to bring it in line with the abstract cache stores provided by Rails that make use of this gem as a backend. As a consequence, this also drops support for Rack 2, so this prerelease is designed to give it a shot in the wild without affecting too many machines, we'll release a full v2.1.0 update in the coming weeks.

Fix nil options in connection pool

A quick bugfix to address #44

Blank Sessions Bugfix

Prevents Redis::Rack from storing blank session data.

redis-actionpack dependency hell

Due to the 2.x release's dependency on Rack 2.0, we need to release this new minor version to keep redis-store up to date without losing the connection to rails 5.