Ensures result lists are always n*max_results long

ping.go

@@ -69,7 +69,7 @@ type Address struct {
 
 func (a Address) Truncate() []float64 {
 	if len(a.results) > a.max_results {
-		a.results = a.results[1:len(a.results)] // return modified slice missing first index
+		a.results = a.results[len(a.results)-a.max_results : len(a.results)] // return modified slice missing first index
 	}
 
 	return a.results