CI: fix pip install (#18990)

Author: jreback

ci/install_travis.sh

@@ -106,6 +106,9 @@ time conda create -n pandas --file=${REQ} || exit 1
 
 source activate pandas
 
+# https://github.com/travis-ci/travis-ci/issues/8920#issuecomment-352661024
+python -c "import fcntl; fcntl.fcntl(1, fcntl.F_SETFL, 0)"
+
 # may have addtl installation instructions for this build
 echo
 echo "[build addtl installs]"