Merge pull request #1021 from minrk/no-pre

don't install prereleases on Travis

.travis.yml

@@ -21,7 +21,7 @@ before_install:
     - 'if [[ $GROUP == js* ]]; then npm install -g casperjs; fi'
     - git clone --quiet --depth 1 https://github.com/minrk/travis-wheels travis-wheels
 install:
-    - pip install -f travis-wheels/wheelhouse --pre file://$PWD#egg=notebook[test] coveralls
+    - pip install -f travis-wheels/wheelhouse file://$PWD#egg=notebook[test] coveralls
 script:
     - 'if [[ $GROUP == js* ]]; then python -m notebook.jstest ${GROUP:3}; fi'
     - 'if [[ $GROUP == python ]]; then nosetests --with-coverage --cover-package=notebook notebook; fi'