mock: addrList fix (#6248)

* improve mock tcp write
* mock addrlist
* add a single mock build in travis

libraries/ESP8266mDNS/src/LEAmDNS_Control.cpp

@@ -25,6 +25,7 @@
 #include <arch/cc.h>
 #include <sys/time.h>
 #include <IPAddress.h>
+#include <AddrList.h>
 #include <lwip/ip_addr.h>
 #include <WString.h>
 #include <cstdint>