Added more items to the test_data.json while testing multithreading

Makefile

@@ -10,5 +10,11 @@ mk_haversine_strtok:
 run_haversine_strtok:
 	cd ./haversine/cpp && ./haverstrtok
 
+mk_test:
+	clang++ -g -lpthread haversine/cpp/test.cpp haversine/cpp/haversine.cpp -o haversine/cpp/test
+
+run_test:
+	cd ./haversine/cpp && ./test
+
 run_haversine_python_json:
 	python ./haversine/python/haversine_json.py