**Overview**

In AWS it is possible to trigger step functions through an API Gateway integration, see https://docs.aws.amazon.com/step-functions/latest/dg/tutorial-api-gateway.html

Similar integrations already occur within localstack, however the step function URIs are notably missing. See lines 66-88 of https://github.com/localstack/localstack/blob/master/localstack/services/apigateway/apigateway_listener.py



┆Issue is synchronized with this [Jira Bug](https://localstack.atlassian.net/browse/LOC-107) by [Unito](https://www.unito.io/learn-more)

self.run_api_gateway_http_integration('custom')
        self.run_api_gateway_http_integration('proxy')
    def run_api_gateway_http_integration(self, int_type):
        test_port = get_free_tcp_port()
        backend_url = 'http://localhost:%s%s' % (test_port, self.API_PATH_HTTP_BACKEND)
        
        proxy = self.start_http_backend(test_port)
        
        result = self.connect_api_gateway_to_http(
            int_type,
            'test_gateway2',
            backend_url,
            path=self.API_PATH_HTTP_BACKEND
        )
        url = gateway_request_url(
            api_id=result['id'], stage_name=self.TEST_STAGE_NAME, path=self.API_PATH_HTTP_BACKEND)