Update skimage version, test CMYK images

BUG=skia:

Change-Id: Id0c9ba3c722304813e3605ef61b87fa00249eaf9
Reviewed-on: https://skia-review.googlesource.com/5449
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Robert Aftias <raftias@google.com>
tree: f7fca5106ed573a8477546ddca0ddc51cacb6b2a
  1. recipe_modules/
  2. recipes.py
  3. recipes/