Element-ui的layout中gutter

## 直接上代码

`

<el-row :gutter=20>

    <el-col :span=8 ><div style="background-color: red">2</div></el-col>

    <el-col :span=8 >div style="background-color: green">2</div></el-col>
    <el-col :span=8 >div style="background-color: green">2</div><el-col>

</el-row>

`

## 效果