argparse==1.2.1
virtualenv==1.7.1.2,==1.7.2,==1.8.2,==1.8.3,==1.8.4,==1.9.1

argparse==1.2.1
virtualenv>=12.0,<13.0

Update virtualenv to 12.0 as older version may no longer exist in pypi
Update virtualenv to 12.0 as older version may no longer exist in pypi
