**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.assertDictEqual(parsed_body.get('return_headers'), {'foo': 'bar123'})
        self.assertDictEqual(parsed_body.get('queryStringParameters'), {'foo': 'foo', 'bar': ['bar', 'baz']})
        request_context = parsed_body.get('requestContext')
        source_ip = request_context['identity'].pop('sourceIp')
        self.assertTrue(re.match(r'^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$', source_ip))
        self.assertEqual(request_context['path'], '/' + self.TEST_STAGE_NAME + '/lambda/foo1')
        self.assertEqual(request_context.get('stageVariables'), None)
        self.assertEqual(request_context['accountId'], TEST_AWS_ACCOUNT_ID)
        self.assertEqual(request_context['resourceId'], resource.get('id'))
        self.assertEqual(request_context['stage'], self.TEST_STAGE_NAME)
        self.assertEqual(request_context['identity']['userAgent'], 'python-requests/testing')
        self.assertEqual(request_context['httpMethod'], 'POST')
        self.assertEqual(request_context['protocol'], 'HTTP/1.1')
        self.assertIn('requestTimeEpoch', request_context)
        self.assertIn('requestTime', request_context)
        result = requests.delete(url, data=json.dumps(data))
        self.assertEqual(result.status_code, 204)
        
        body_msg = '🙀 - 参よ'
        result = requests.post(url, data=json.dumps({'return_raw_body': body_msg}))
        self.assertEqual(to_str(result.content), body_msg)
    def test_api_gateway_lambda_proxy_integration_any_method(self):
        self._test_api_gateway_lambda_proxy_integration_any_method(
            self.TEST_LAMBDA_PROXY_BACKEND_ANY_METHOD,
            self.API_PATH_LAMBDA_PROXY_BACKEND_ANY_METHOD)
    def test_api_gateway_lambda_proxy_integration_any_method_with_path_param(self):
        self._test_api_gateway_lambda_proxy_integration_any_method(
            self.TEST_LAMBDA_PROXY_BACKEND_ANY_METHOD_WITH_PATH_PARAM,
            self.API_PATH_LAMBDA_PROXY_BACKEND_ANY_METHOD_WITH_PATH_PARAM)
    def test_api_gateway_authorizer_crud(self):