Fixed circular dependency

morphology_features imports WormFeatures, but WormFeatures
imports
morphology_features.

I fixed this by moving
WormFeatures._extract_time_from_disk to utils.py
so that
morphology_features no longer needs to import WormFeatures.

Fixed circular dependency

morphology_features imports WormFeatures, but
WormFeatures imports
morphology_features.

I fixed this by moving
WormFeatures._extract_time_from_disk to utils.py
so that
morphology_features no longer needs to import WormFeatures.