allow SDWebImage 3.7 or any version newer, up to 5 (#205)
allow SDWebImage 3.7 or any version newer, up to 5 (#205)

The latest release of SDWebImage is at 4.1.2, so we say <5 to note that this
library hasn't been tested against that major version (if and when it's
released).
zvonicek/ImageSlideshow,zvonicek/ImageSlideshow