Added unit testing with Catch2 framework

src/makefile

@@ -12,5 +12,14 @@ main.o: main.cpp config.hpp
 config.o: config.cpp config.hpp
 	$(CXX) $(CXXFLAGS) -c config.cpp
 
+tests: tests.o config.o
+	g++ -std=c++17 -Wall tests.o config.o -o tests -lCatch2Main -lCatch2
+
+tests.o: tests.cpp config.hpp
+	$(CXX) $(CXXFLAGS) -c tests.cpp
+
+check: tests
+	./tests
+
 clean:
-	rm -f *.o blog
+	rm -f *.o blog tests