Flechas slider liso mudam

$(document).ready(function(){
        $('.slider').slick({
            autoplay:true,
            arrows: true,
            prevArrow:"<button type='button' class='slick-prev pull-left'><i class='fa fa-angle-left' aria-hidden='true'></i></button>",
            nextArrow:"<button type='button' class='slick-next pull-right'><i class='fa fa-angle-right' aria-hidden='true'></i></button>"
        });
    });
Said HR