Support for latest MomentJs

[Hendrikv1990]

Hey there,

Not sure if still is still actively maintained, but I am giving it a try.

I got this issue when I upgrade rails, with that, ofcourse momentjs also updated. Then daterangepicker needs to be updated.

In daterangepicker.js line 42 > this.locale. There are some issues on the way _lang() is used. I solved it as follows. It's a bit ugly, but it would be great if a similar fix comes in the future, or if there will be support for future versions. Otherwise I will load the regular daterangepicker as a separate js file.

Thanks!

`var ld = moment().localeData()
console.log(ld._weekdaysMin.slice());

    this.locale = {
        applyLabel: 'Apply',
        cancelLabel: 'Cancel',
        fromLabel: 'From',
        toLabel: 'To',
        weekLabel: 'W',
        customRangeLabel: 'Custom Range',
        daysOfWeek: ld._weekdaysMin.slice(),
        monthNames: ld._monthsShort.slice(),
        firstDay: 0
    };`