Bullet list with 3 levels not working

Hi,

I'm not sure if this project is still actively maintained. I've got an issue with making bullet lits with at least 3 levels, it only renders to the second level in the HTML output.

Example markdown :

# Test

- one
- two
  - three
    - four 
    - five
  - six
- seven

And here's a screenshot of the output :