Simple sidekick discovery unit(s) were mutating the same path

Previously the doc resulted in both units mutating the same path in
etcd: "/services/website/apache1" (where the last would win). With
this change two files are written. I also added an "@" char as I was
getting confused between apache1 (old apache) vs the first apache :)

core@core-01 ~ $ etcdctl ls /services/ --recursive
/services/website
/services/website/apache@1
/services/website/apache@2