v1.6.0

• Adapters - Support for Rails 6.1 and above (Adapters::ActiveRecord, Adapters::ActiveSupportCache, ActiveSupportCache::MonetaStore)
• Adapters::YAML - add theadsafe option
• Adapters::Sequel - fix deadlock issue with #increment on MySQL in newer Sequel versions (#244)
• Adapters::Sequel - fix issue with Postgres HStore on newer Postgres (#243)
• Adapters - fixed an issue many adapters had where #merge! errored if passed an empty hash (#246)
• Support changes - Drop support for 2.3 and 2.4, add support for 3.x