add basic function test

update travis to run function test

test/function_test/vpc/CMakeLists.txt

@@ -0,0 +1,24 @@
+cmake_minimum_required(VERSION 3.0)
+project(demo)
+set(CMAKE_CXX_STANDARD 11)
+if(CMAKE_HOST_WIN32)
+    include_directories("C:\\Program Files (x86)\\alibabacloud-sdk\\include")
+    link_directories("C:\\Program Files (x86)\\alibabacloud-sdk\\lib")
+endif()
+
+# note ft_build is the dir you build sdk
+include_directories("../../../core/include/")
+include_directories("../../../vpc/include/")
+link_directories(${CMAKE_SOURCE_DIR}/ft_build/lib)
+
+add_executable(vpc_ft vpc_describeNatGateways_ft.cc)
+target_link_libraries(vpc_ft alibabacloud-sdk-core alibabacloud-sdk-vpc)
+
+target_link_libraries(vpc_ft core gtest gmock_main)
+
+set_target_properties(vpc_ft
+  PROPERTIES
+  OUTPUT_NAME ${TARGET_OUTPUT_NAME_PREFIX}vpc_ft
+  RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+
+add_test(NAME vpc_ft COMMAND vpc_ft)

test/function_test/vpc/vpc_describeNatGateways_ft.cc

@@ -0,0 +1,27 @@
+#include <iostream>
+#include "../utils.h"
+#include "gtest/gtest.h"
+#include "alibabacloud/core/AlibabaCloud.h"
+#include "alibabacloud/vpc/VpcClient.h"
+
+using namespace std;
+using namespace AlibabaCloud;
+using namespace AlibabaCloud::Vpc;
+
+namespace {
+  TEST(vpc, describeNatGateways) {
+    utUtils utils;
+    string key = utils.get_env("ENV_AccessKeyId");
+    string secret = utils.get_env("ENV_AccessKeySecret");
+    InitializeSdk();
+    ClientConfiguration configuration("cn-hangzhou");
+    VpcClient client(key, secret, configuration);
+    Model::DescribeNatGatewaysRequest request;
+    request.setPageSize(10);
+    auto outcome = client.describeNatGateways(request);
+    EXPECT_TRUE(outcome.isSuccess());
+    EXPECT_TRUE(outcome.error().errorCode().empty());
+    EXPECT_TRUE(outcome.result().getTotalCount() == 0);
+    ShutdownSdk();
+  }
+}