Revert "lock down the redis version"

This reverts commit 8c942ca7149afff241c968f66669b17c7e36ca4e. and dd4b938365d0f6196206fd7c70056c34477d13d5
Revert "Use new 'robust' subscription scheme"

This reverts commit dd4b938365d0f6196206fd7c70056c34477d13d5