add proper test for stringify helper

src/lib.rs

@@ -28,12 +28,16 @@ mod tests {
         let mut handlebars = Handlebars::new();
         register(&mut handlebars);
 
-        println!("{:?}", handlebars.render_template("{{JSONstringify foo}}", &json!({
-            "foo": {
-                "bar": 1,
-                "baz": 2
-            }
-        })).unwrap());
+        let foo = json!({
+            "bar": 1,
+            "baz": 2
+        });
+        assert_eq!(
+            handlebars.render_template("{{JSONstringify foo}}", &json!({
+                "foo": foo
+            })).unwrap(),
+            foo.to_string()
+        );
     }
 
     #[test]