update to highcharts new version

[lesliesu]

Hi, I have got some issues while using highcharts boot.module.js options. I noticed that that module has some updates in their new version and would like to have a try, it would be great that this library update the depedency to the latest version.

[pgscada]

I had the same issue. I put a dependency on the newest highcharts dependency in package.json and it resolved my issues.

[patrickhernon]

+1 to have this library updated to use version 6.x