It looks like a duplicate of old issue https://github.com/localstack/localstack/issues/78
But now it's reproducible for me with the latest version of LocalStack. 
path = '/'
        resources = {}
        resource_path = path.lstrip('/')
        resources[resource_path] = []
        for method in methods:
            resources[resource_path].append({
                'httpMethod': method,
                'integrations': [{
                    'type': 'AWS_PROXY',
                    'uri': target_uri
                }]
            })
        return aws_stack.create_api_gateway(
            name=gateway_name,
            resources=resources,
            stage_name=self.TEST_STAGE_NAME
        )
    def create_lambda_function(self, fn_name):
        zip_file = testutil.create_lambda_archive(
            load_file(TEST_LAMBDA_PYTHON),
            get_content=True,
            libs=TEST_LAMBDA_LIBS,
            runtime=LAMBDA_RUNTIME_PYTHON27
        )
        testutil.create_lambda_function(
            func_name=fn_name,
            zip_file=zip_file,
            runtime=LAMBDA_RUNTIME_PYTHON27
        )