Log user in using Passwordless service
    :param pending_id: PendingExternalToMainUser's id
    :param ticket: ticket returned from Passwordless
    :param response: Response object from webapp2
    :param detail_url: url to check ticket and user data
    :return: a Command that log user in when executed

def login_checking_email(pending_id, ticket, response, detail_url='https://pswdless.appspot.com/rest/detail'):
    """
    Log user in using Passwordless service
    :param pending_id: PendingExternalToMainUser's id
    :param ticket: ticket returned from Passwordless
    :param response: Response object from webapp2
    :param detail_url: url to check ticket and user data
    :return: a Command that log user in when executed
    """
    return LoginCheckingEmail(pending_id, ticket, response, USER_COOKIE_NAME, detail_url)