Update mws/mws.py
Update mws/mws.py

replacing md5 with hashlib.md5
ziplokk1/python-amazon-mws,bpipat/mws,czpython/python-amazon-mws,GriceTurrble/python-amazon-mws,bloodywing/python-amazon-mws,BigFlySports/python-amazon-mws,juokaz/python-mws-sdk,hairyjerry/python-amazon-mws,jameshiew/mws,Bobspadger/python-amazon-mws