Spilo-9.4-0.75-p1

New version of Spilo, incorporating Patroni 0.6 and 0.75 releases. Brings you the ability to use configurable replication_methods, tags (nofailover), the command-line client patronictl (you have to run it from inside the docker container with docker exec) and a lot of bug fixes.

The image can be obtained from registry.opensource.zalan.do/acid/spilo-9.4:0.75-p1. Note that at the moment it relies heavily on the stups.io infrastructure, particularly Taupage (which, in itself, has some other dependencies).