elementui 修改全局组件默认值

import ElementUI from 'element-ui'
// 以input和select举例， 输入框默认展示清空按钮
ElementUI.Input.props.clearable = {type: Boolean, default: true}
ElementUI.Select.props.clearable = {type: Boolean, default: true}
ElementUI.Cascader.props.clearable = {type: Boolean, default: true}