fix(template): throw when no way to deal with the template type

Author: vvo

lib/utils.js

@@ -15,6 +15,8 @@ function renderTemplate(template, data) {
     content = hogan.compile(template).render(data);
   } else if (typeof template === 'function') {
     content = template(data);
+  } else {
+    throw new Error('Template must be `string` or `function`');
   }
 
   return content;