barcharts crash on zoom with a lot of data

[fbertanha]

thanks for this great library port!

When a set a lot of data in barcharts and apply zoom in/out the app stop with the error below. im using the demo app in my iOS device iPhone 7.

stack trace in xcode:
2019-09-30 23:41:26.337733-0300 Runner[1930:141345] flutter: Another exception was thrown: Unsupported operation: Result of truncating division is Infinity or NaN

[SunPointed]

I already fix this issue you could have a try. You can check this https://github.com/SunPointed/mp_flutter_chart/commit/a01aa31212ad976dde5bf411a4f2ca69aa391e7d