CI: rigorously test k-v.io
CI: rigorously test k-v.io

We make sure that each of the three nameservers
(ns-{aws,azure,gce}.sslip.io) can set a key-value, that the value
propagates to the remaining nameservers, that a nameserver can delete a
key, and that the deletion propagates to the remaining nameservers.

cunnie/sslip.io,cunnie/sslip.io,cunnie/sslip.io,cunnie/sslip.io