add ipython to conda env

Author: amueller

ci_scripts/install.sh

@@ -25,7 +25,7 @@ popd
 # Configure the conda environment and put it in the path using the
 # provided versions
 conda create -n testenv --yes python=$PYTHON_VERSION pip nose \
-   numpy=$NUMPY_VERSION scipy=$SCIPY_VERSION cython=$CYTHON_VERSION matplotlib scikit-learn nbconvert nbformat jupyter_client
+   numpy=$NUMPY_VERSION scipy=$SCIPY_VERSION cython=$CYTHON_VERSION matplotlib scikit-learn nbconvert nbformat jupyter_client ipython
 source activate testenv