Adds ifndef to headers

src/core/include/EventBus.hpp

@@ -1,6 +1,9 @@
+#ifndef EVENT_BUS_HPP
+#define EVENT_BUS_HPP
+
 class EventBus {
     public:
     EventBus();
 };
 
-
+#endif

src/core/src/main.cpp

@@ -1,13 +1,13 @@
 #include <iostream>
-//#include "resolver/Resolver.hpp"
+#include "Resolver.hpp"
 #include "EventBus.hpp"
 
 int main(int args, char **argv) {
     using std::cout;
     using std::endl;
 
-      EventBus eventBus();
-//    Resolver resolver();
+    EventBus eventBus();
+    Resolver resolver();
 
     cout << "Hello there!" << endl;