voc parser

[yrodriguezmd]

Previous parser code throws error 'voc has no parser module'.

Changed code to

parser = parsers.VOCBBoxParser(annotations_dir= path/'Annotations', images_dir = path/'JPEGImages', class_map=class_map)

This one worked for me, so I'm forwarding the suggestion.

[lgvaz]

Good catch! This is indeed something we changed on icevision a while back.

Thanks for the PR!