update book code

eBook/examples/chapter_8/maps_forrange.go

@@ -1,13 +1,15 @@
-package main
-import "fmt"
-
-func main() {
-    map1 := make(map[int]float32)
-    map1[1] = 1.0
-    map1[2] = 2.0
-    map1[3] = 3.0
-    map1[4] = 4.0
-    for key, value := range map1 {
-        fmt.Printf("key is: %d - value is: %f\n", key, value)
-    }
-}
+package main
+
+import "fmt"
+
+func main() {
+	map1 := make(map[int]float32)
+	map1[1] = 1.0
+	map1[2] = 2.0
+	map1[3] = 3.0
+	map1[4] = 4.0
+
+	for key, value := range map1 {
+		fmt.Printf("key is: %d - value is: %f\n", key, value)
+	}
+}