BUILD: nose version conflict in pkg_resources.
See https://travis-ci.org/pydata/pandas/jobs/33461059

```
The command "echo "script"" exited with 0.
0.18s$ ci/script.sh
inside ci/script.sh
nosetests --exe -w /tmp -A not slow and not disabled pandas --with-xunit --xunit-file=/tmp/nosetests.xml
Traceback (most recent call last):
  File "/home/travis/virtualenv/python3.4.1/lib/python3.4/site-packages/pkg_resources.py", line 449, in _build_master
    ws.require(__requires__)
  File "/home/travis/virtualenv/python3.4.1/lib/python3.4/site-packages/pkg_resources.py", line 745, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/home/travis/virtualenv/python3.4.1/lib/python3.4/site-packages/pkg_resources.py", line 644, in resolve
    raise VersionConflict(dist, req)
pkg_resources.VersionConflict: (nose 1.3.3 (/home/travis/virtualenv/python3.4.1/lib/python3.4/site-packages), Requirement.parse('nose==1.3.4'))
```

Trying to reproduce locally right now. Hopefully we just need to bump the nose version.
