Add example test file

test/hello_test.cc

@@ -0,0 +1,9 @@
+#include <gtest/gtest.h>
+
+// Demonstrate some basic assertions
+TEST(HelloTest, BasicAssertions) {
+    // Expect two strings not to be equal.
+    EXPECT_STRNE("hello", "world");
+    // Expect equality.
+    EXPECT_EQ(7 * 6, 42);
+}