Generate a c7n-org subscriptions config file

def main(output):
    """
    Generate a c7n-org subscriptions config file
    """

    client = SubscriptionClient(Session().get_credentials())
    subs = [sub.serialize(True) for sub in client.subscriptions.list()]
    results = []
    for sub in subs:
        sub_info = {
            'subscription_id': sub['subscriptionId'],
            'name': sub['displayName']
        }
        results.append(sub_info)

    print(
        yaml.safe_dump(
            {'subscriptions': results},
            default_flow_style=False),
        file=output)