adds vendor directory

vendors dependencies in standard `vendor` directory, managed by glide

vendor/github.com/mattn/go-gtk/example/locale/locale.go

@@ -0,0 +1,17 @@
+package main
+
+import "github.com/mattn/go-gtk/gtk"
+import "github.com/mattn/go-gtk/glib"
+import "fmt"
+import "syscall"
+
+func main() {
+	gtk.SetLocale()
+
+	bs, _, _, err := glib.LocaleFromUtf8("こんにちわ世界\n")
+	if err == nil {
+		syscall.Write(syscall.Stdout, bs)
+	} else {
+		fmt.Println(err.Message())
+	}
+}