Feature Request: Support a border radius prop fro the crop selection area

[zackcon]

Would be great to add some border radius to create a rounded squared on the crop selection area, similar to the circularCrop prop.

[sample-tayo]

you can just target it directly from your global css file like this

.ReactCrop__crop-selection {
border: 4px solid #e4572e !important;
animation: none !important;
background-image: none !important;
}