*: use discovery.etcd.io not etcd-discovery

I had renamed this repo long ago but had never fixed this. Fix!
Merge pull request #6 from philips/rename-fix

*: use discovery.etcd.io not etcd-discovery
WIP dockerfile
make Discovery base URL configurable
add DISCOVERY_ROOT_URL for discovery configable
change into centos
change into entrypoint
figured out entrypoint
test on bash
Dockerfile
change to CMD
add DISCOVERY_ORIGIN_ADDR
update REAMDE
fix array
add INIT_LEADER