Verify that install_requires is a valid requirements list

def check_requirements(dist, attr, value):
    """Verify that install_requires is a valid requirements list"""
    try:
        list(pkg_resources.parse_requirements(value))
    except (TypeError,ValueError):
        raise DistutilsSetupError(
            "%r must be a string or list of strings "
            "containing valid project/version requirement specifiers" % (attr,)
        )