Suppress the warning of uninteresting call.

The API call in the constructor and deconstructor are not watched.
Add EXPECT_CALL().

test/test_mockgpiobasic.cpp

@@ -9,11 +9,18 @@
 #include "gpiobasic.hpp"
 #include "sdkwrapper.hpp"
 
+using ::testing::_;
 class MockGpioBasicTest : public ::testing::Test {
  protected:
-  virtual void SetUp() { gpio = new rpp_driver::MockGpioBasic(sdk_); }
+  virtual void SetUp() {
+    EXPECT_CALL(sdk_, gpio_init(_));
+    gpio = new rpp_driver::MockGpioBasic(sdk_);
+  }
 
-  virtual void TearDown() { delete gpio; }
+  virtual void TearDown() {
+    EXPECT_CALL(sdk_, gpio_deinit(_));
+    delete gpio;
+  }
 
   ::rpp_driver::MockSdkWrapper sdk_;
   ::rpp_driver::MockGpioBasic *gpio;
@@ -23,4 +30,4 @@ class MockGpioBasicTest : public ::testing::Test {
  * In this test case, we test teh MockGpioBasic is surely able to compile.
  * So, none of the other methods are tested.
  */
-TEST_F(MockGpioBasicTest, constructor) {}
+TEST_F(MockGpioBasicTest, Constructor) {}