Update Phone.txt

Phone.txt

@@ -20,7 +20,7 @@ class Phone {
         send requesting packet to lock
         return the state of the given lock
     }
-    bool set(ElectronicDevice device, bool state){
+    bool sendSignal(ElectronicDevice device, bool state){
         send packet to device 
         return true if success, false if no response received
     }