fix main.rs_template

src/main.rs_template

@@ -9,8 +9,8 @@ use cmd_sample::CommandSample;
 use cmd_default::CommandDefault;
 
 fn main() -> CommandError {
-    let commands = vec![
-        CommandSample{},
+    let commands: Vec<Box<dyn Command>> = vec![
+        Box::new(CommandSample{}),
     ];
     let mut app = App::new(env!("CARGO_PKG_NAME"))
                     .version(env!("CARGO_PKG_VERSION"))