Update bear_backup.py
Update bear_backup.py

Updated paths to reflect Bear 1.6 update.

Source: http://help.shinyfrog.net/discussions/bear/7085-lost-notes-after-time-machine-restore

However, I do receive errors during the backup, not sure why.

```Traceback (most recent call last):
  File "/usr/local/bin/bear_backup.py", line 171, in <module>
    if note.existing_file_is_newer():
  File "/usr/local/bin/bear_backup.py", line 85, in existing_file_is_newer
    filename = self.full_filename()
  File "/usr/local/bin/bear_backup.py", line 82, in full_filename
    return pathlib.Path(self.filename()).with_suffix(".bearnote")
  File "/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/lib/python3.7/pathlib.py", line 819, in with_suffix
    raise ValueError("%r has an empty name" % (self,))
ValueError: PosixPath('.') has an empty name```
mivok/bear_backup,mivok/bear_backup