Added pragma once directive to Service

Service.h

@@ -1,9 +1,10 @@
+#pragma once
 #include <string>
 #include "Weather.h"
 
 class Service {
 public:
     virtual ~Service() = default;
-    
+
     virtual Weather getWeather(std::string s) = 0;
 };

XmlService.h

@@ -5,4 +5,4 @@ class XmlService : public Service {
 public:
     virtual Weather getWeather(std::string s) override;
     virtual ~XmlService() {}
-};
+};