Add unit testing back

test/CMakeLists.txt

@@ -0,0 +1,15 @@
+include(${CMAKE_SCRIPTS_DIR}/googletest.cmake)
+set(current_target opengl-starter-test)
+
+add_executable(
+  ${current_target}
+  test_main.cpp
+)
+
+target_link_libraries(
+  ${current_target}
+  gtest_main
+)
+
+include(GoogleTest)
+gtest_discover_tests(${current_target})

test/test_main.cpp

@@ -0,0 +1,6 @@
+#include <gtest/gtest.h>
+
+TEST(testmain, example)
+{
+    EXPECT_EQ(42, 7*6);
+}