shadowObj.spread miscalculation
Sometimes shadowObj.spread has type of string, instead of int. This lead to miscalculation of innerShadow.spread in [line 158 of file nodeToSketchLayers.js](https://github.com/brainly/html-sketchapp/blob/master/html2asketch/nodeToSketchLayers.js#L158):
`shadowObj.spread += parseInt(borderWidth, 10);`

For example:
`shadowObj.spread = "0"; // string, not an number!`
`shadowObj.spread += parseInt("0px", 10); // → "00", should be 0`

To fix this:
`shadowObj.spread = parseInt(shadowObj.spread, 10) + parseInt(borderWidth, 10);`