update book code

eBook/examples/chapter_10/use_person2.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"fmt"
+	"./person"
+)
+
+func main() {
+	p := new(person.Person)
+	// error: p.firstName undefined (cannot refer to unexported field or method firstName)
+	// p.firstName = "Eric"
+	p.SetFirstName("Eric")
+	fmt.Println(p.FirstName()) // Output: Eric
+}