TST: Add nose-timer to travis.

.travis.yml

@@ -20,9 +20,10 @@ install:
   - grep nose-parameterized== etc/requirements_dev.txt | xargs pip install
   - grep nose-ignore-docstring== etc/requirements_dev.txt | xargs pip install
   - pip install coveralls
+  - pip install nose-timer
 before_script:
   - "flake8 zipline tests"
 script:
-  - nosetests --exclude=^test_examples --with-coverage --cover-package=zipline
+  - nosetests --with-timer --exclude=^test_examples --with-coverage --cover-package=zipline
 after_success:
   - coveralls