Again import error in branch package update:

ERROR: Failure: ImportError (No module named skimage.morphology)

  File "/local/gitlab-runner/builds/6b02994f/0/bob/bob.bio.vein/env/lib/python2.7/site-packages/bob/bio/vein/preprocessors/TopographyCutRoi.py", line 13, in <module>
    from skimage.morphology import convex_hull_image
ImportError: No module named skimage.morphology

E.g. - https://gitlab.idiap.ch/bob/bob.bio.vein/builds/12936