fix typo - change conn to con
Merge pull request #4127 from tshauck/fix-io-typo

fix typo - change conn to con
BLD: install pip serially
Merge pull request #4141 from cpcloud/travis-install-pip-serially

BLD: install pip serially
BLD: readd missing envar in ci/install.sh
BLD: add lxml back in
BLD: travis, drop -I from scikits install