added python-ply dependence
added python-ply dependence

Change-Id: Ie8db0fd7774bc470a18600a9c01989ec2649c2f2

chenm001/connectal,hanw/connectal,csail-csg/connectal,8l/connectal,csail-csg/connectal,chenm001/connectal,hanw/connectal,csail-csg/connectal,chenm001/connectal,8l/connectal,cambridgehackers/connectal,chenm001/connectal,8l/connectal,hanw/connectal,hanw/connectal,hanw/connectal,cambridgehackers/connectal,cambridgehackers/connectal,cambridgehackers/connectal,8l/connectal,csail-csg/connectal,chenm001/connectal,csail-csg/connectal,8l/connectal,cambridgehackers/connectal