List saved lead lists

{  "data": [    {      "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",      "account_id": "449e7a5c-69d3-4b8a-aaaf-5c9b713ebc65",      "name": "string",      "description": "string",      "column_layout": [        {}      ],      "created_at": "2019-08-24T14:15:22Z",      "updated_at": "2019-08-24T14:15:22Z"    }  ]}

{  "error": {    "type": "authentication_error",    "code": "invalid_api_key",    "message": "A valid Furnace API key is required"  }}

{  "error": {    "type": "rate_limit_error",    "code": "rate_limit_exceeded",    "message": "Rate limit exceeded for this account"  }}

{  "error": {    "type": "api_error",    "code": "internal_error",    "message": "Internal server error"  }}