Initialize Git user config file.

    :param kwargs: key/value pairs are stored in the git user config file.

def user_config(**kwargs):
    """
    Initialize Git user config file.

    :param kwargs: key/value pairs are stored in the git user config file.
    """
    for kw in kwargs:
        git('config --global user.%s "%s"' %(kw, kwargs.get(kw))).wait()