update book code

eBook/exercises/chapter_7/string_split2.go

@@ -0,0 +1,15 @@
+package main
+
+import "fmt"
+
+func main() {
+	str := "Google"
+	str2 := Split2(str)
+	fmt.Printf("The string %s transformed is: %s\n", str, str2)
+}
+
+func Split2(s string) string {
+	mid := len(s) / 2
+	return s[mid:] + s[:mid]
+}
+// Output: The string Google transformed is: gleGoo