Add verify_split to API documentation?

[mjordan]

https://github.com/MetaArchive/bagit-split/blob/master/bag-split.py#L21 provides API documentation for the 'unsplit()' method. Should similar docs for 'verify_split()' (function at https://github.com/MetaArchive/bagit-split/blob/master/bag-split.py#L79) be added as well? E.g.,

API Usage:
  bag = unsplit("/parent/dir/of/bags")
  is_split = verify_split("/path/to/dir/of/bags")