日期加一天；（减一天类似，时间加减类似）获取当前日期

调用：this.minDate();2019-04-30

minDate =()=>{
    //日期加一天
     let date = new Date(this.state.date1);
     date.setDate(date.getDate() + 1);
     let month = date.getMonth() + 1;
     let day = date.getDate();
     return date.getFullYear() + '-' + this.getFormatDate(month) + '-' + this.getFormatDate(day);
};
getFormatDate =(arg)=> {
    if (arg === undefined || arg === '') {
        return '';
    }
    let re = arg + '';
    if (re.length < 2) {
        re = '0' + re;
    }
    return re;
};