Add general iostream lib access.

Com_server/test/src/Com_SerialWritingThread.cpp

 /**
- *  @author Sylvain Colomer
+ *  @author Sylvain Colomer, P. Gaussier
  *  @date 18/04/19.
  */
 
+#include <iostream>
+#include <string>
+
+using namespace std;
+
 #include "../include/Com_SerialWritingThread.h"
 #include "../include/global_variables.h"