Ensure to write .new images on image dimension mismatch
Changelog
Version: 3.0.1
Fixes a minor issue that when the image dimensions are not the same it now generates the .new images as before (previously the image dimension mismatch was handled by compare, but now it appears that its possible that it will return the diff pixel count. So now we've implemented a check, which didn't correctly follow the same workflow as before. It does now.