Highcharts version update

[Bodata]

Hi,
I found you are using highcharts 6.0.3 in your gem.
I trying to get a custom pattern working, but it fails to load a file

This is working:

data: [{
            name: "Pop",`
            low: 1483228800000,
            high: 1496275200000,
            color: "url(#highcharts-default-pattern-1)"
        }]

However this is not working:

data: [{
            name: "Pop",`
            low: 1483228800000,
            high: 1496275200000,
            color: {
                pattern: {
                    image: "https://upload.wikimedia.org/wikipedia/commons/thumb/1/1a/Flag_of_South_Dakota.svg/640px-Flag_of_South_Dakota.svg.png",
                }
            }
        }]

I think it could be because the example's are made with Highcharts 6.1.

Are you planning to upgrade to the latest version of HighCharts ?
Or am i doing something wrong ?

Regards,
Peter