beforeChange returning incorrect newIndex index int

See example here:
https://codesandbox.io/s/react-slick-playground-forked-ref07

In the latest version (0.27.11) there is a bug in the beforeChange callback. See the console log returns `2.7` for the newIndex rather than `3` for the last slide.

Changing the package version to 0.26 shows expected (`3`) value for the new index arg on the last slide.