Fix python tests
Fix python tests


Former-commit-id: 5fab95f48c92d91846d63987c89821474909b57c
xunzhang/dynet,xunzhang/dynet,shuheik/dynet,clab/cnn,danielhers/dynet,danielhers/dynet,danielhers/dynet,shuheik/dynet,xunzhang/dynet,clab/cnn,clab/dynet,shuheik/dynet,clab/dynet,xunzhang/dynet,chunyang-wen/dynet,clab/dynet,clab/dynet,shuheik/dynet,chunyang-wen/dynet,clab/cnn,danielhers/dynet,clab/dynet,danielhers/dynet,shuheik/dynet,danielhers/dynet,clab/dynet,danielhers/dynet,clab/dynet,chunyang-wen/dynet,shuheik/dynet,chunyang-wen/dynet,shuheik/dynet