discovery: support size para
Merge pull request #11 from xiangli-cmu/size

discovery: support size para
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
seprate Docker file
fix URL trim schema double slash