print version number on mixing
indents were mistakenly modified
test ok
add some test
indentation was mistakenly modified
adjust to cpplint
versions should be output in MIX slave's log too
use `server_ip` and `server_port` instead of `ip_` and `port_`
Merge pull request #649 from jubatus/feature/print_model_version

Print versions of models in MIX log