sqs.changeMessageVisibility according to [this](https://docs.aws.amazon.com/AWSSimpleQueueService/latest/APIReference/API_ChangeMessageVisibility.html#API_ChangeMessageVisibility_Examples) makes a request directly to the Queue's URL rather than via the SQS Endpoint. (I'm already setting SQS endpoint to LOCALSTACK_HOSTNAME - makes no difference for this call)..

In localstack the queue URL host returned is by default set to the value of HOSTNAME_EXTERNAL, which I'm setting to localstack, but calling this method within a lambda, does not work and I get the error:

```
UnknownEndpoint: Inaccessible host: `localstack'. This service may not be available in the `us-east-1' region. 
```

So, how can I make the queue URL accessible from within a lambda using localstack? Effectively I need to make **http://localstack** accessible from within lambda.

I'm using the following cmd to start localstack:

```
LAMBDA_EXECUTOR=docker-reuse DEBUG=1 LAMBDA_REMOTE_DOCKER=0 DATA_DIR=/tmp/localstack/data HOSTNAME_EXTERNAL=localstack localstack start
```
TEST_STAGE_NAME = 'testing'
    TEST_LAMBDA_PROXY_BACKEND = 'test_lambda_apigw_backend'
    TEST_LAMBDA_PROXY_BACKEND_WITH_PATH_PARAM = 'test_lambda_apigw_backend_path_param'
    TEST_LAMBDA_PROXY_BACKEND_ANY_METHOD = 'test_lambda_apigw_backend_any_method'
    TEST_LAMBDA_PROXY_BACKEND_ANY_METHOD_WITH_PATH_PARAM = 'test_lambda_apigw_backend_any_method_path_param'
    TEST_LAMBDA_SQS_HANDLER_NAME = 'lambda_sqs_handler'
    TEST_LAMBDA_AUTHORIZER_HANDLER_NAME = 'lambda_authorizer_handler'
    TEST_API_GATEWAY_ID = 'fugvjdxtri'
    TEST_API_GATEWAY_AUTHORIZER = {
        'name': 'test',
        'type': 'TOKEN',
        'providerARNs': [
            'arn:aws:cognito-idp:us-east-1:123412341234:userpool/us-east-1_123412341'
        ],
        'authType': 'custom',
        'authorizerUri': 'arn:aws:apigateway:us-east-1:lambda:path/2015-03-31/functions/' +
                         'arn:aws:lambda:us-east-1:123456789012:function:myApiAuthorizer/invocations',
        'authorizerCredentials': 'arn:aws:iam::123456789012:role/apigAwsProxyRole',
        'identitySource': 'method.request.header.Authorization',
        'identityValidationExpression': '.*',
        'authorizerResultTtlInSeconds': 300
    }
    TEST_API_GATEWAY_AUTHORIZER_OPS = [
        {
            'op': 'replace',
            'path': '/name',
            'value': 'test1'
        }
    ]
    def test_api_gateway_kinesis_integration(self):