BLD: force numpy 1.6.1 most everywhere on travis

Author: y-p

ci/install.sh

@@ -18,13 +18,10 @@ pip install $PIP_ARGS --use-mirrors cython nose python-dateutil pytz
 
 if [ ${TRAVIS_PYTHON_VERSION} == "3.2" ]; then
     sudo apt-get $APT_ARGS install python3-numpy;
-fi
-
-# or else, get it with pip and compile it
-if [ ${TRAVIS_PYTHON_VERSION} == "2.6" ]; then
-     pip $PIP_ARGS install numpy;
 elif [ ${TRAVIS_PYTHON_VERSION} == "3.3" ]; then # should be >=3,3
     pip $PIP_ARGS install https://github.com/numpy/numpy/archive/v1.7.0.tar.gz;
+else
+     pip install numpy==1.6.1
 fi
 
 # Optional Deps