slightly better python packaging
slightly better python packaging


Former-commit-id: 69309b19f91e55d5a8d0c0fa8f47eab92cf7a938
clab/dynet,chunyang-wen/dynet,danielhers/dynet,danielhers/dynet,clab/dynet,shuheik/dynet,shuheik/dynet,chunyang-wen/dynet,danielhers/dynet,danielhers/dynet,clab/cnn,xunzhang/dynet,xunzhang/dynet,clab/dynet,chunyang-wen/dynet,xunzhang/dynet,clab/dynet,clab/cnn,danielhers/dynet,shuheik/dynet,shuheik/dynet,clab/dynet,xunzhang/dynet,danielhers/dynet,shuheik/dynet,clab/dynet,chunyang-wen/dynet,clab/cnn,shuheik/dynet,clab/dynet,danielhers/dynet,shuheik/dynet