title: Set highcharts y-axis min value to 0, unless there is negative data
body: <p>I'm having an issue with highcharts where I have a number of different charts being generated by JSON calls. </p>
  
  <p>For the majority of these charts I need the minimum y-axis value to be set at 0, however there are a couple of occasions where negative values need to be shown. How can I tell highcharts to have a minimum y-axis value of 0 only if there are no negative values in the data, is this even possible?</p>
  
  <p>Thanks</p>