Fixed bug where .cache directory does not exist during test
Fixed bug where .cache directory does not exist during test

stiphyMT/plantcv,AntonSax/plantcv,stiphyMT/plantcv,jshoyer/plantcv,AntonSax/plantcv,danforthcenter/plantcv,stiphyMT/plantcv,danforthcenter/plantcv,jshoyer/plantcv,danforthcenter/plantcv