Rename the hello subdirectory to test

test/hello.cpp

@@ -0,0 +1,18 @@
+#include <iostream>
+
+class Hello {
+public:
+    Hello() {
+        printf("Hello ctor\n");
+    }
+    ~Hello() {
+        printf("Hello dtor\n");
+    }
+};
+
+Hello global_h;
+
+int main(int argc, char* argv[]) {
+    std::cout<<"Hello world C++"<<std::endl;
+    return 0;
+}