Added fix for parsing fileList in highcharts-convert.js from [SO](http://stackoverflow.com/questions/38294099/highcharts-and-phantomjs-error-cant-find-variable-highcharts) and [upstream](https://github.com/highcharts/highcharts-export-server/issues/18) to this package. I was getting the same error as in stack overflow and this fixed it.
Added fix for parsing fileList in highcharts-convert.js from [SO](http://stackoverflow.com/questions/38294099/highcharts-and-phantomjs-error-cant-find-variable-highcharts) and [upstream](https://github.com/highcharts/highcharts-export-server/issues/18) to this package. I was getting the same error as in stack overflow and this fixed it.

zejacobi/highcharts-export-server