Update nose requirement to 1.3.4
Update nose requirement to 1.3.4

This will make our Travis CI builds run a little faster. Right now,
the `pip install -r requirements.txt` uninstalls 1.3.4 to install
1.3.3.

Medium/ClusterRunner,josephharrington/ClusterRunner,nickzuber/ClusterRunner,box/ClusterRunner,box/ClusterRunner,nickzuber/ClusterRunner,josephharrington/ClusterRunner,Medium/ClusterRunner