Fixed setuptools issue in travis build

.travis.yml

@@ -21,7 +21,8 @@ before_install:
 - if [ -n "${NUMPYSPEC}" ]; then pip install --find-links http://wheels.astropy.org/ --find-links http://wheels2.astropy.org/ --use-wheel numpy$NUMPYSPEC; fi
 - pip install --find-links http://wheels.astropy.org/ --find-links http://wheels2.astropy.org/ --use-wheel sphinx nose==1.3.0 jinja2==2.6 cpp-coveralls pygments==1.6
 install:
-- python bootstrap-buildout.py
+- SETUPTOOLS_VERSION=`python -c "import setuptools; print setuptools.version.__version__"`
+- python bootstrap-buildout.py --setuptools-version $SETUPTOOLS_VERSION
 - CFLAGS=-coverage ./bin/buildout
 script:
 - ./bin/python -c 'from bob.io.base import get_config; print(get_config())'