Get a dictionary of file paths and timestamps.

    Paths matching `exclude` regex will be excluded.

def get_hashes(path, exclude=None):
    '''
    Get a dictionary of file paths and timestamps.

    Paths matching `exclude` regex will be excluded.
    '''
    out = {}
    for f in Path(path).rglob('*'):
        if f.is_dir():
            # We want to watch files, not directories.
            continue
        if exclude and re.match(exclude, f.as_posix()):
            retox_log.debug("excluding '{}'".format(f.as_posix()))
            continue
        pytime = f.stat().st_mtime
        out[f.as_posix()] = pytime
    return out