版本：
文件：
- https://cdn.bootcdn.net/ajax/libs/formbuilder/0.2.1/formbuilder-min.css
- https://cdn.bootcdn.net/ajax/libs/formbuilder/0.2.1/formbuilder-min.js
- https://cdn.bootcdn.net/ajax/libs/formbuilder/0.2.1/formbuilder.css
- https://cdn.bootcdn.net/ajax/libs/formbuilder/0.2.1/formbuilder.js