put a secret called `name` into the secret-store,
    protected by the key kms_key

def putSecret(name, secret, version="", kms_key="alias/credstash",
              region=None, table="credential-store", context=None,
              digest=DEFAULT_DIGEST, comment="", **kwargs):
    '''
    put a secret called `name` into the secret-store,
    protected by the key kms_key
    '''
    if not context:
        context = {}
    session = get_session(**kwargs)
    kms = session.client('kms', region_name=region)
    key_service = KeyService(kms, kms_key, context)
    sealed = seal_aes_ctr_legacy(
        key_service,
        secret,
        digest_method=digest,
    )

    dynamodb = session.resource('dynamodb', region_name=region)
    secrets = dynamodb.Table(table)

    data = {
        'name': name,
        'version': paddedInt(version),
    }
    if comment:
        data['comment'] = comment
    data.update(sealed)

    return secrets.put_item(Item=data, ConditionExpression=Attr('name').not_exists())