Inject logger instead of using a singleton

src/logger.hpp

@@ -3,17 +3,14 @@
 
 class Logger
 {
-private:
-	Logger();
-	~Logger();
-
 public:
 	void Success(const std::string & s);
 	void Error(const std::string & s);
 	void Info(const std::string & s);
+	void Debug(const std::string & s);
 
-	static Logger & GetInstance();
-
+	Logger();
+	~Logger();
 	Logger(Logger & other) = delete;
 	Logger(Logger && other) = delete;
 	Logger & operator=(Logger & other) = delete;