BLD: fix conda version

Author: jreback

ci/install_travis.sh

@@ -76,7 +76,9 @@ fi
 bash miniconda.sh -b -p $HOME/miniconda || exit 1
 
 conda config --set always_yes yes --set changeps1 no || exit 1
-conda update -q conda || exit 1
+
+# fix the conda version
+conda install conda==4.0.8
 conda config --add channels http://conda.anaconda.org/pandas || exit 1
 conda config --set ssl_verify false || exit 1