Fixed DeprecationWarning related to skimage.measure.compare_ssim. Added...

Fixed DeprecationWarning related to skimage.measure.compare_ssim. Added minimal version of scikit-image. Updated HISTORY.rst.

Signed-off-by: Daniel Scheffler <danschef@gfz-potsdam.de>
2 jobs for enhancement/fix_ssim_deprecationwarning in 43 seconds (queued for 16 minutes and 55 seconds)