ignores acutal image widths when scaling with CSS transforms

resposively-lazy does not support CSS Transforms (e.g. scale) with calculations of actual image widths

This can be fixed by using element.getBoundingClientRect().width instead of element.offsetWidth

change
var containerWidth = container.offsetWidth * window.devicePixelRatio;
to
var containerWidth = container.getBoundingClientRect().width * window.devicePixelRatio;

Demo
https://codepen.io/thcreate/pen/700d3a105243db29443d236fcf858626

[ivopetkov]

Sounds correct. Can you please push the change.