I'm trying to setup an lambda function triggered by S3 events within a localstack docker-compose environment.
I've got the latest localstack image running in one service with S3, Lambda and APIGATEWAY and the second service is using `awslocal` to communicate with the localstack.

I have gotten as far as successfully creating a lambda function but when I attempt to `add-permission` I get a 404 Not Found error.

My command is:
```
awslocal lambda add-permission 
--function-name my-lambda-function 
--action lambda:InvokeFunction 
--statement-id s3 
--principal s3.amazonaws.com 
--source-arn arn:aws:s3:::event-source-bucket
```

This works against AWS so I'm not sure what I need to have setup within localstack to get it working.  Thanks for any insight you may have.
""" Create new event source mapping
        ---
        operationId: 'createEventSourceMapping'
        parameters:
            - name: 'request'
              in: body
    """
    data = json.loads(to_str(request.data))
    mapping = add_event_source(data['FunctionName'], data['EventSourceArn'], data.get('Enabled'))
    return jsonify(mapping)
@app.route('%s/event-source-mappings/<mapping_uuid>' % PATH_ROOT, methods=['PUT'])
def update_event_source_mapping(mapping_uuid):
    """ Update an existing event source mapping
        ---
        operationId: 'updateEventSourceMapping'
        parameters:
            - name: 'request'
              in: body
    """
    data = json.loads(request.data)
    if not mapping_uuid:
        return jsonify({})
    function_name = data.get('FunctionName') or ''
    enabled = data.get('Enabled', True)
    batch_size = data.get('BatchSize') or 100
    mapping = update_event_source(mapping_uuid, function_name, enabled, batch_size)
    return jsonify(mapping)
@app.route('%s/event-source-mappings/<mapping_uuid>' % PATH_ROOT, methods=['DELETE'])
def delete_event_source_mapping(mapping_uuid):