rename from keeper to proxy
disable workdir by default
change model extension from js to jubatus
change key name of default config
add test target in Makefile
update for client 0.5.0
remove unused import
add generator support (experimental)
add wait_for_servers method in proxy
refactor configuration DSL interface; make constants available in DSL
add nearest_neighbor, clustering and binary values support to constants
improve README
improve envdef.py example
Merge branch 'fix-0.5.0'