Version update for skimage.measure compare_psnr and compare_ssim

[SameerAdavani]

To run the code change "from skimage.measure.simple_metrics import compare_psnr " to " from skimage.metrics import peak_signal_noise_ratio as compare_psnr " and
"from skimage.measure import compare_ssim" to
from skimage.metrics import structural_similarity as compare_ssim
in utils/image_utils.py

These are the new version update for skimage