Using coveralls wheel from idiap wheel server

.travis.yml

@@ -21,7 +21,7 @@ before_install:
 - sudo apt-get install -qq --force-yes libboost-all-dev libblitz1-dev texlive-latex-recommended texlive-latex-extra texlive-fonts-recommended
 - pip install --find-links https://www.idiap.ch/software/bob/wheels/travis/ --use-wheel -r requirements.txt
 - pip install --find-links https://www.idiap.ch/software/bob/wheels/travis/ --use-wheel sphinx$SPHINXSPEC nose==1.3.0 jinja2==2.6 coverage cpp-coveralls pygments==1.6
-- pip install --pre coveralls
+- pip install --find-links https://www.idiap.ch/software/bob/wheels/travis/ --use-wheel coveralls
 install:
 - python bootstrap-buildout.py
 - CPPFLAGS=--coverage LDFLAGS=--coverage ./bin/buildout buildout:debug=false buildout:develop=. buildout:extensions=bob.buildout buildout:auto-checkout=