Temporarily added some output in order to find out package versions.

On pandas-dev's CI instances this branch didn't fail for py2
although on top of pandas.io.excel there is an import
from "http.client" which is only available in py3.
This change should clarify why this happens and should be removed later.

Author: mcrot

ci/install_travis.sh

@@ -159,6 +159,18 @@ echo
 echo "[show pandas]"
 conda list pandas
 
+echo
+echo "[show final conda list]"
+conda list
+
+echo
+echo "[show version of python interpreter]"
+python --version
+
+echo
+echo "[try to import http.client]"
+python -c "import http.client"
+
 echo
 echo "[done]"
 exit 0