This is causing problems with the `fancy_arrow` test:

```bash
File "/home/travis/virtualenv/python2.6/lib/python2.6/site-packages/matplotlib/axis.py", line 332, in apply_tickdir
self._tickmarkers = (mlines.TICKUP, mlines.TICKDOWN)
AttributeError: 'module' object has no attribute 'TICKUP'
```

Maybe add these back in and add a comment? These (or the tests) should probably be refactored.