需求：将默认的可全选改为只能单选

1.隐藏全选框

<style lang="scss" scoped>
	// /deep/  !important
	thead .el-table-column--selection .cell {
		display: none!important;
	}
</style>

2.单选

<el-table ref="multipleTable" @selection-change="handleSelectionChange">

handleSelectionChange(val) {
	if(val.length > 1) {
		this.$refs.multipleTable.clearSelection();               //清除
        this.$refs.multipleTable.toggleRowSelection(val.pop());  //pop：最后一个
	} else {
        this.multipleSelection = val;         //multipleSelection：当前选择的数组
	}
}