Get the aggregated total steps for a specific day (starting and ending at midnight).An optional options object may be provided containing `date` field representing the selected day. If `date` is not set or an options object is not provided then the current day will be used.```javascriptletd=newDate(2016,1,1);letoptions={date:d.toISOString()};``````javascriptAppleHealthkit.getStepCount(options:Object,(err:Object,results:Object)=>{if(err){return;}console.log(results)});``````javascript{value:213,}```