unittest on appveyor

ixwebsocket/IXDNSLookup.cpp

@@ -6,9 +6,18 @@
 
 #include "IXDNSLookup.h"
 
+#ifdef _WIN32
+# include <basetsd.h>
+# include <WinSock2.h>
+# include <ws2def.h>
+# include <WS2tcpip.h>
+# include <io.h>
+#else
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netdb.h>
+#endif
+
 #include <string.h>
 #include <chrono>