Pagination Dots Not Activating Correctly with decimal Values for slidesToShow and infinite: false.

### Hello,

I've found an issue where the pagination dots do not behave as expected when a user sets an decimal number for `slidesToShow `(e.g., 1.5) and `infinite `is set to false.

In this scenario, the last pagination dot doesn't become active (the class "slick-active" isn't applied) when the last "page" of slides is visible. Pls use navigation buttons to slide.

For a demonstration of the problem, please view the CodeSandbox example I've put together:

https://codesandbox.io/s/react-slick-playground-forked-p5gmx6

I look forward to any suggestions for resolving this issue.

Thanks!