fix bit_index_storage to erase rows with empty vector on MIX
fix bit_index and inverted_index erase rows locally
Remove serialization methods for clustering
remove unnecessary namespace prefix
Use relative import for py3
Merge pull request #697 from jubatus/remove-unused-serialize

Remove serialization methods for clustering
Merge pull request #685 from jubatus/fix-684

fix bit_index_storage to erase rows with empty vector on MIX
Merge pull request #724 from jubatus/fix-659

fix bit_index and inverted_index erase rows locally
fix code style in inverted_index_storage.cpp (refs #685)
Merge pull request #712 from jubatus/py3

Use relative import for py3
eliminate random number without seed in clustering tests (fix #718)
remove unused annotations in IDL (fix #714)
Fix dead-lock caused by re-entrant lock acquisition over put_diff RPC: fixes #723
Fix RPC error handling in linear_mixer
Merge pull request #727 from jubatus/fix-718

eliminate random number without seed in clustering tests (fix #718)
fix set_label argument name to new_label (refs #706)
Return error code with `unknown error`
Merge pull request #731 from jubatus/fix-729

Fix RPC error handling in linear_mixer: fixes #729