Remove get_key() method from versioner and key_versioner
Adapt tests for key_versioner/versioner get_key() removal
Implement master-version feature in redis to handle version store unavailability
Adapt and improve tests a bit
Changelog
Style and opinion
Change exceptions naming convention (Failure -> Error)
Add unittest for Redis cache client
Merge branch 'master' of https://github.com/pior/pyramid_caching into pior-master
Merge branch 'pior-master'
merge